Biker's-Bicycle Maintenance Guide and Riding Tips

Introduction and Table of Contents

I often get asked about bicycle maintenance and repairs, and tips for how to ride efficiently. This little manual is intended as a summary of what I have learned over the years. I am not a professional mechanic. All of what I say here is the result of personal experience and opinion and may in places flatly contradict professional techniques, but it has served me well. I offer no guarantees that it will work for you. If your bicycle falls apart because I said something wrong, you are on your own.

(*) Wheels


* Hubs, spokes, rims, inner tubes, tire liners, tires

* Preventing Punctures

* Repairing Punctures

* Fixing a Rubbing Wheel

* Replacing a Rim



(*) Steering



* Handlebars

* Headset

* What is a headset?

* Selecting a headset

* Checking the adjustment

* Adjustment and repair



(*) The drive train

* Brakes

* Gear Shift Levers

* Chainwheels, Cogs, and Chains

* Replacing a Chain

* Selecting a Gear Range

* Pedals


* Shoes


* Derailleurs

* Saddle


(*) Bicycle computers


* Riding computers


* Avocet vs. Cateye

* Heart rate monitors

* GPS Satellite navigation

* Taking Good Pictures


(*) Clothes

* Pants

* Shirts

* Shoes

* Gloves

* Helmet

* Glasses



(*) Riding

* Riding in Town

* Riding Long Distances

* Riding in a Group



(*) Travel tips


* Packing list


* Immigration and Customs


* Good and Bad Airlines

* Shipping Bicycles by Train

* Shipping Bicycles by Air

* Panniers



(*) What to do in an accident

* After the accident

* Dealing with insurances


* The criminal trial

Wheels



* Hubs, spokes, rims, inner tubes, tire liners, tires

* Preventing Punctures

* Repairing Punctures

* Fixing a Rubbing Wheel

* Replacing a Rim

Hubs,Spokes,Rims,Inner Tubes,Tyre Liners,Tyres

Wheels consist of the following components:

* The hub, containing an axle, the quick-release inside the axle, and two or more bearings holding the rotating hub body with the flanges that hold the spokes. The quick-release is an ``inner axle'' with a nut on one end and a lever on the other, and two conic springs that simplify installation. The small ends of the springs point to the center of the hub. The nut should be tightened such that closing the lever is hard but can be done with one hand (how is that for an imprecise unit of measurement :-) A loose quick release can cause the rear axle to shift in the dropouts when accelerating hard, causing the tire to rub, or in the worst case can work itself even looser until you are in danger of losing the entire wheel.

There are two kinds of hubs, obsolete freewheel ones where the sprocket assembly contains the coasting bearings and ratchets that screws onto the hub itself, and cassette hubs where the bearings and ratchets are built into the hub and the sprockets are fixed. Do not under any circumstances use the former type; they contain a bearing that runs near the center of the hub that can bend the axle. The latter type has bearings on both ends where they can't bend the axle. A bent axle can bend or break the right dropout of the frame, and you'll have to write off the entire frame! It happened to me twice.

* There are usually 36 spokes. Some people prefer 32 for reasons that are not clear to me, or even 28. Tandems can benefit from 48 spokes. Staying with 36 spokes offers the widest selection of hubs and rims. There are double-butted spokes that are narrower in the middle where there is less load, bladed spokes, wavy spokes, and other exotica. Double-butted spokes make sense (spokes always break at the neck or where the threading begins), the rest is fairly useless. Bladed and wavy spokes are also more difficult to install because they twist and make it hard to gauge tension. Spoke thickness is usually measured in ``gauge''; smaller numbers indicate larger diameter.

Spoke length is important, but computing the right length is a black art. Generally, all spokes of the front wheel have the same length. Sprocket-side (right) rear spokes are shorter, outer (left) rear spokes are slightly longer because the right rear hub flange is close to the center of the hub. When buying replacements bring an old spoke. Up to a millimeter too short doesn't hurt, but spokes that are too long can puncture the inner tube.

Wheels can be built radial, 3-cross, and 4-cross. Radial means that spokes run straight to the rim without crossing; 3-cross and 4-cross refer to the number of times a spoke crosses other spokes. 3-cross is standard. There is no reason to use radial wheels except aesthetic reasons; it reduces the strength of the wheel and makes the ride rougher. Obviously, each of these spoke patterns requires a different spoke length. By the way, always use steel spokes and brass nipples.

* There are many types of rims: rectangular profiles (like Mavic MA-2 or Campagnolo Delta), aero profiles (like Campagnolo Omega), and anything in between. High-quality rims are machined to avoid the normal seam where the rim joins; this seam can catch the brake pads and cause uneven wear and braking behavior. Don't buy black-anodized rims; the anodization will be quickly worn away where the brake pads rub against it.

* I swear by Campagnolo rims. Mavic is ok, but look at their high-end double-butted rims - the holes are apparently punched, not drilled, and if you hold them just right you can see small discolorations where the metal was deformed. This weakens the rim, and just now (9/99) two spoke sockets were torn from my rim at such points, leaving huge holes. Campagnolo rims are drilled and finished perfectly. My current favorite is the Moskva 80, but they no longer make it.

* Inside the rim, rim tape protects the inner tube from the spoke ends. There are two types, adhesive textile tape and tough hard plastic. Both work equally well but the hard plastic is difficult to remove without tools while the textile tape may expose the inner tube to spoke holes if chosen too narrow. Reinstalling the hard plastic type can lead to mysterious flats because the tape lenghtens during removal, and when the tire is reinflated the tape may get pushed aside or into the spoke holes until the tube touches sharp metal edges of the rim. When you take it apart to find the reason for the puncture, it shifts back into place, hiding the problem. Use adhesive textile tape if possible.

Aero rims are stiffer but are more difficult to install because spoke nipples have a tendency to get lost. Always use aluminum rims, steel rims brake dangerously poorly in wet weather despite brake pad manufacturers' claims. Make sure the rim does not just have spoke holes drilled into it but some kind of steel sleeve that protects the hole. Absolutely never buy an aluminum rim if there are discolorations on the outside around each spoke hole when held against the light. Discolorations indicate that the holes were punched rather than drilled; rims like that can fail abruptly when the hole cracks and spokes pull out. I have destroyed several Mavic MA2 rims that way when touring with bags.

* Inner tubes come in butyl and latex, in various weights. 100-gram butyl is best. 60-gram butyl is too vulnerable to snakebite punctures, and latex leaks air and can rip off the valve if the tire slips for any reason. Choose a valve stem that is threaded all the way to the tip without any smooth parts because pumps tend to hold poorly to smooth valve stems.

There are two types of valves, Presta (French) or Schrader (like those used on cars). Presta valves are narrower and are always used for racing bicycles; Schrader valves are found on mountainbikes. Presta is easier to pump because one doesn't have to work against a spring. Don't forget to unscrew the nipple before pumping. The maximum pressure allowed depends on the tire; it is printed on the side of the tire. One bar is approximately 14 psi; road tires usually hold 8-9 bar. Don't underinflate because you are more vulnerable to snakebite punctures; don't overinflate because the tire can pull off the rim and cause nasty crashes if the loose tire edge gets caught in the brake.

Don't buy a pump that inflates the tire with both in and out motions. You need to wait for the builtin valves to restore air pressure in the pump at both ends of the stroke, which takes several seconds so it takes forever to inflate the tire. It sounds like a good idea but you'll hate it after three seconds. The best frame pumps ever built are the aluminum Zefal X3 and X4 pumps; they have a cap that twists to lock the internal spring so that all the force put into it directly translates to tire pressure. Brilliant. Unfortunately few stores carry them.

* Tire liners are Kevlar belts that are inserted between the inner tube and the tire to prevent punctures by sharp objects. More on that below.

* Tires for road bikes should always be bald (smooth, untreaded). It may be counter-intuitive but they have higher traction. Fatter tires make for a smoother ride on rough roads or when touring loaded; narrow tires deform less and waste less energy. I prefer 20mm front and 23mm rear tires (but watch out, different manufacturers seem to rate their tires differently).

There are Kevlar-beaded (foldable) and Kevlar-belted (puncture-proof) tires. Puncture-proof tires aren't, because the belt is too narrow. On the contrary, it seems to be hard to laminate smooth Kevlar to the outer rubber layer, I have had tires come apart. My latest trip to France (2001) saw two brand-new Vittoria tires with Kevlar belts come apart after a few days, which first pulled the tire into an S curve and then developed a fuzzy hole. I do not buy Vittoria tires anymore, and some shops have stopped selling them.

Make sure the side wall is strong enough. My favorites are foldable non-belted Avocet road (not Criterium!) tires; they last practically forever and still have a rubber that is soft enough to afford traction on wet roads. Recommended. Too bad that they only make the wide versions anymore. These days I mostly use Continental tires; a little heavy but very robust.

See also an article on "Preventive Punctures"

Preventing Punctures

Inner tubes puncture for two reasons: either a sharp object penetrated the tire or worked its way between tube and tire, or the wheel "bottomed out" and the tube got pinched between rim and tire. The latter usually causes a pair of telltale "snakebite" punctures.

Punctures caused by sharp objects such as nails, wires broken off from street-cleaning machines, and glass can almost always be prevented with a Kevlar tire liner. At this point I used to recommend ``Mr. Tuffy's'', but recent experiences have shown that they cause way more flats than they prevent because the hard edges rub against the tube until it blows out. No amount of sanding and melting with a lighter has fixed this. They used to have a soft version that worked well, but the current version, recognizable by the black stripe, is dangerous. Don't buy! If you must use them, cut the end straight off and only soften the corners a bit; don't cut a long soft curve because it's the sides that eat into the tube. There is a ``green slime'' brand that spares the tube, but it's a little on the soft side and lets some debris pass, and only lasts a year or two before it falls to pieces. Still seems to be the best bet right now (2004).

Snakebites are caused when hitting an obstacle such as a pothole hard so the inner tube gets pinched between the rim and the obstacle. Tire liners help very little here. The best prevention is to inflate the tube to exactly the pressure printed on the side of the tire at all times, and rechecking the pressure at least every other week because butyl inner tubes leak air. Latex tubes are nearly puncture-proof but leak air at a frightening rate.

Do not use light-weight tubes. Some of them weigh 60 grams or less, but are very prone to punctures. If you use tire liners, occasionally check for pieces of glass that became lodged in the tire; they can work their way into the tire if left in long enough. Look as if you knew what you are doing when cutting away at your tire with a knife point. Do not use ``Wrench Force'' tubes, they have inferior valves that break easily when installing.



See also an article on "Repairing Punctures"

Repairing Punctures

You need two plastic tire levers, a pump, and either a repair kit or a new inner tube. Let all air out of the tube and push the tire towards the center, away from the rim, all around the wheel. Insert the spoon-shaped part of one tire lever between the rim and the tire at the place where you suspect the puncture, scoop the tire out of the rim, and hook the other end into a spoke. Very carefully insert the spoon end of the lever only as far as needed to prevent pinching the tube. Repeat two spoke holes away from the first with the other lever. Repeat until you can pull the tube out of the tire.

If you are on the road and have a spare tube, it is usually best to install it and fix the punctured tube at home, in a warm and dry place. This requires removing the wheel by releasing the quick-release lever in the axle. In the case of the rear wheel, shift to the smallest rear sprocket first. Mountainbikes sometimes require unscrewing the quick-release nut partway because of ridges in the dropout that prevent accidentally losing a wheel when the quick-release comes loose.

Small holes can be fixed by glueing a patch. I have never managed to reliably patch a hole more than a millimeter or two in length. If the hole is large, an air bubble will form under the patch and find a way out. Snakebites require a large patch that covers both holes. Pump up the tube to find the hole. Let nearly all the air out of the tube again, clean and dry the tube around the hole, and use the sandpaper to roughen the area. File off seam protrusions. Apply a thin coat of glue that is larger than the patch. Patiently wait until it dries, which takes a couple of minutes (impatience is rewarded with a patch that comes loose soon). Apply the patch and press on hard at the center and all around the edges. Continental patches seem to be the best. Always push the air out of the glue tube when replacing the cap so it won't dry up quickly.

To reinstall the tube, inflate it so it just barely holds its shape. Insert the valve and push the tube into the tire there. Working away from the valve, push the tube into the tire while slightly pushing it towards the valve. Alternatingly work from the left and right of the valve to prevent the valve from being pulled in one direction. If the tube is so long that a loop remains after it is fully installed, don't squeeze it in but pull it all the way out again and retry, this time pushing it harder towards the valve. The goal is to keep the tension of the tube constant along the circumference of the wheel. It's easier than it sounds. If you have a tire liner, always keep it centered, and place the overlap of the liner ends at the side opposite from the valve.

Push the open end of the tire into the rim beginning at the valve, taking special care that the tube is not trapped between rim and tire, and work away from the valve. Usually it is hard to push in the last bit on the opposite side. First try pushing the tire towards the center of the rim while pulling it towards the remaining loop. If this is not sufficient, let all air out of the tire.

If all this fails (and only then), you need the tire levers again. Put a little bit of air into the tube so it holds its round shape and insert the spoon-shaped end of a tire lever between tire and rim, but with the "wrong" side up - not hooking into the rim but with the inner side of the curve towards the tire. This makes it harder to push the tire in but reduces the risk of pinching the tube. Begin near the ends and work towards the middle of the section not yet pushed in. You can use the hook end of the other lever to keep the tire from pushing out of the rim at the other end.

Sometimes the wall of the tire gets punctured. This is dangerous because the tube will form a bubble there that can explode with a loud bang. Torn tire walls are unfixable but you can keep the tube inside by inserting a folded dollar bill or some other denomination of your choice. Paper money is incredibly strong and will last years if the hole is not too large. If the threads in the side wall are damaged so much that the tire bends out of shape after inflating, it's unfixable, you need a new tire. Obviously, don't do dangerous downhills with such a fix, it will probably fail at the worst possible moment.



See also an article on "Fixing a Rubbing Wheel"

Fixing a Rubbing Wheel

If your rim rubs against the brake pads in a few places, the wheel needs to be retrued. This can be done safely only if the rim is undamaged; if it was bent, for example by bottoming out on a curb, the procedure still works if the damage isn't too great but it won't last long - spokes may snap or unscrew.

I am assuming that you are using aluminum rims. If you have steel rims the procedure is the same but takes much longer because not only the spokes near the rubbing spot are involved but all other spokes too.

First, use chalk to mark the range that is rubbing. In that range, either loosen the spokes on the rubbing side or tighten the spokes on the other side. Compare the tension of the spokes in that area to the tension of spokes elsewhere to decide which of the two is right; if you can't feel a difference do both. Use a spoke wrench to adjust all spokes in the rubbing area; the ones in the center of more than the ones where the rubbing area begins and ends. Never turn the nipple more than one quarter turn at a time. If in doubt whether to tighten one side or loosening the other, go for tightening because slack spokes can unscrew all the way while riding. After adjusting, grab every crossing pair of spokes on both sides with your hand and pull them together hard (this releases tensions built when spokes are twisted). Test whether the rubbing spot got smaller, and repeat the procedure until the problem is gone.

There is usually no point in tuning the wheel better than one millimeter, that is, to less than a sideways wobble of 1mm relative to the brake pads. It often helps to move the brake pads closer together than normal to identify wobbles.

See also an article on "Replacing a Rim"

Replacing a Rim

Bicycle wheels need to be properly adjusted for smooth riding and to prevent the rim from rubbing against the brake pads. The most common cause for misadjusted wheels are accidents and lack of maintenance. A rim with a dent or other damage is practically impossible to realign; any attempt to do so by pulling it back into shape will cause broken spokes, or spokes that continuously unscrew and go slack. Replacing a rim is much easier than building a wheel from scratch.

Buy a new rim with the same number of holes and the same inner diameter. The inner diameter is smaller for some "aero" rims. Avoid black-anodized rims because the anodizing will rub off after a while. Always use aluminum rims, never use steel. Steel is hard to true and brakes poorly even with special brake pads.

Place the old wheel flat on a table and tape the new rim to the old one, making sure that the valve holes line up. Also make sure that the spoke hole pattern lines up if the holes are alternatingly offset left and right from the center. Next, loosen all old nipples but do not completely unscrew any of them. Beginning with the spokes ending at the flange facing up, unscrew the nipple and move the spoke to the new rim, one at a time. A few turns of the nipple suffice. Apply a small amount of grease to the threads before screwing on the nipple. Continue with the remaining spokes until none are attached to the old rim, which you can now remove. The wheel will be very floppy at this stage. To avoid losing nipples in the rim, screw the wrong side one turn into a spare spoke, which you can then use as a handle.

If the old rim was built with the correct spoke lengths (which are different on the left and right side for the rear wheel), the threading of the spokes was completely covered by the nipples. Now carefully tighten all the nipples until the threading is just barely hidden. This must be done carefully because it ensures lateral trueness. All spokes will still be rather loose after this. I use a power screwdriver. Next, beginning at the valve, tighten every nipple with a spoke wrench by one half-turn, in sequence, until you reach the valve hole again. Repeat until all spokes feel about as tight as they were in the original wheel. For rear wheels, tighten the spokes on the sprocket side much more than the ones on the outer side to keep the rim in the center. This sort of happens automatically with the above method because the sprocket-side spokes are shorter than the outer ones, but it helps to complete the sprocket side before beginning with the outer side. Get a feel for the spoke tension before taking apart the old wheel.

The wheel is now tight but not true. Install it on the bicycle and turn the wheel to see where it rubs against a brake pad. If it does not turn at all or rubs in too many places, loosen the brake cable so that the brake pads move away from the rim. In places where the brake pads rub, tighten the opposite spoke until it no longer rubs. Always tighten neighboring spokes too. Never tighten a nipple by more than a quarter-turn at a time before rechecking. If a spoke seems to become much tighter than its neighbors, loosen the spokes on the opposite side (i.e. ending at the hub flange on the rubbing side) instead of further tightening. When the rim no longer rubs against the brake pads, move the brake pads closer together and repeat, until there is about one millimeter between the pads and the rim on either side, on average.

During trueing, periodically pull every pair of neighboring spokes on one side together as hard as possible with one hand. This releases tension that builds up in the spokes during trueing because tightening nipples also twists the spoke. It may help to pluck spokes and comparing the pitch of the sound, but I find this method hard to use and inaccurate.

After the wheel is finished, reinstall the rim tape, the tire, and the tube, inflate, and ride around the block a few times, then recheck the wheel by releasing tension again and checking trueness. Traditionally, tires are mounted such that the label is at the valve on the right (chain) side of the bicycle.

Check out the site of DT Swiss, the largest maker of bicycle spokes. Their glossary is very good.

See also technical articles on "Steering"

Steering


* Handlebars

* Headset

* What is a headset?

* Selecting a headset

* Checking the adjustment


* Adjustment and repair

Handlebars

The Components

Since I ride road bicycles, I prefer drop handlebars. When seen from the side, they form an U lying on its side. They afford many different hand positions: on the flat top part, holding the brake handles, on the ends, or between the ends and the handles. With some, the curved part is nearly semicircular; I prefer the kind made by Modolo and others where the curved part has another straight section directly below the brakes. It's not so convenient to grasp a curved part of the handlebar. Some handlebars have one or two grooves that help installing brake and (for Campagnolo Ergopower) shifting cables. In comparison, straight handlebars like those usually used on mountainbikes only afford a single hand position, and a fairly unnatural one with the palms facing down that makes my hands hurt after a while.

The handlebars are held in the center by the stem. On road bicycles, the stem is angled downward to compensate for the angle of the steering tube of the bicycle frame, such that the top of the stem that holds the handlebars is horizontal. There are stems that angle upward, but this raises the handlebars and forces the rider into a more upward position that increases wind resistance.

There are various types of aero bars, also called triathlon bars. The most common types are clamped to the top of the handlebars. There are many different types. My current favorite is Syntace, despite the prices that border on extortion (little required pieces of plastic need to be bought separately at unreal prices). They clamp on the thick inner part of the handlebars, leaving more room for holding the top of the handlebars, they have a very low height and comfortable and adjustable armrests, and they have just the right length and a steep front that doesn't require bending the wrists too much.

Are aero bars necessary? This depends on the kind of riding you do. I began using them when I had a 19-km ride to work every day into a persistent headwind. They also offer an edge when it's my turn at the front during group rides. They are not useful for short trips, and they can be dangerous in the city because it takes longer to reach the brakes, and because they move the center of gravity forward and increase the danger of the rear wheel losing contact with the ground when braking. They cannot be used when climbing hills. They should never be used with old-fashioned brake levers with brake cables coming out of the top because it's easy to get one's gloves caught when reaching for the brakes.
Adjusting the Handlebars

The lower part of the stem should be long enough to raise the top to about the level of the top of the saddle, or a few centimeters lower. Lower position decrease wind resistance but put more strain on the neck muscles. The top of the stem is not normally set higher than the top of the saddle. The length of the top part of the stem should be chosen depending on the length of the top tube of the frame; usually it's longer for people with a long upper body compared to the length of the legs. Care should be taken to choose a solid stem that does not flex when pulling hard on the handlebars, like when standing to get up a steep hill.

Some people recommend to adjust the drop handlebars such that their ends point to the center of the seat tube of the frame (the one that runs from the bottom bracket to the seat post). This makes me feel like I am sliding off the ends, so I adjust mine to be almost horizontal, angled downward very slightly. The straight section in the curve allows an angled hand position anyway. This angle must be chosen before anything else is installed.

The brake levers are adjusted next after choosing the angle of the handlebars. They should be installed such that they can be comfortably held with your hands on the brake lever body, and they can be reached easily when the hands hold the curved part of the handlebars. For me, this means that the rubber body is about horizontal, installed at the forward-most (vertical) section of the handlebars. This must be done before installing the handlebar tape and cutting the cables; it's very difficult to make adjustments later. Do not use "safety brake levers" that have an extra lever that extends back towards the stem; they brake poorly and give a false sense of security.

The aero bar angle is also pretty much a matter of taste. I prefer the aero bars angling slightly up towards the front end. Any larger angle would hurt my forearms resting on the armrests.
Handlebar Tape
The handlebar, and many aero bars, need to be wrapped with tape. The tape should have an adhesive strip running along the back, and should be a soft foam or cork material. I have found Cinelli to be the best; unfortunately it's expensive. Real cork does not last long. The cheap material that looks like artificial leather is uncomfortable. Choose a dark or mottled color that won't look dirty quickly.

Before wrapping the tape, install any brake and shifter cables that run to the brake handles or the bar-end shifters, using the grooves in the handlebars if available. Tape the cables to the handlebars with electrical tape to they don't come off all the time during wrapping.

Wrapping begins by attaching the short strips to the metal strap that holds the brake levers to the handlebar. Fold back the rubber coating of the brake lever body. Next, cut off one edge of one of the long handlebar strips so it tapers towards the end, remove the end of the backing to expose the adhesive strip, and begin wrapping at the end of the handlebar (not at the center near the stem). Wrap clockwise on the right side and counter-clockwise on the left side, seen from the rear of the bicycle (this prevents unwrapping when holding the handlebars on the top later). Wrap under tension, but not enough to stretch the tape significantly. The loops should be spaced such that the adhesive strip is just barely on the handlebar, not on the previous loop of the tape. I tend to space the loops more closely near the end and wider near the stem.

When you reach the brake lever, make sure that the last loop folds against the brake lever body. The next loop extends all the way to the other side of the brake lever body. Some people recommend to then fold the tape to run back along the lever to the lower end and then back over the previous loop than spanned the body, only in the other direction so it crosses the previous loop, but I find it makes the brake lever section too fat and wastes too much tape. Then complete wrapping the tape to the place where the handlebar gets wider near the stem, taper the ends again, and seal the end with electrical tape or the adhesive strips in the handlebar package. I usually have to re-wrap the last part after the brake lever a few times to get the length just right.

If you have aero bars that clamp on the narrow part of the handlebars, not the wide part near the stem, remember to leave enough of the handlebars untaped to install the aero bar brackets. When folding back the rubber brake body coat no part of the handlebar metal should be visible. For this purpose, put a 10cm piece of tape across the clamp that holds the brake handle, with the ends disappearing under the rubber cover of the handlebars after they are peeled back in place.


See also an article on "Headset"

Headset

What is a headset?

The headset is the pair of bearings on both ends of the head tube of the frame. Installing a headset involves pressing cups into the head tube and a ring onto the fork, which can't be done without expensive tools that align all three to be exactly parallel, which usually requires filing off uneven paint. It's one of the few things I let the bicycle shop do.

See also "What is a head set"

What is a headset?

The headset is the pair of bearings on both ends of the head tube of the frame. Installing a headset involves pressing cups into the head tube and a ring onto the fork, which can't be done without expensive tools that align all three to be exactly parallel, which usually requires filing off uneven paint. It's one of the few things I let the bicycle shop do.

See also an article on " Selecting a Headset"

Selecting a headset

The selection of headsets depends on the length of the fork. The fourth, remaining bearing race is part of a nut that is screwed onto the threaded top end of the fork after it has been inserted into the head tube. Some headsets need more threading to stick out at the top of the head tube than others. If the fork is too long, spacer rings can be inserted, but if it is too short you are restricted to a small selection of headsets. Unfortunately, the rather poor-quality Shimano headsets are among them, which could force you to stick with the same poor headsets. I broke quite a lot of them until I spent an enormous sum on a Chris King headset, and never again had any trouble. I am convinced that if the sun ever goes nova, nothing will be left of our planet except hot gas and orbiting Chris King headsets. They are indestructible and worth every penny.
Checking the adjustment

Headsets break when the bearing balls crush the hardened surface of the bearing races. This happens when the metal of the races is too soft or the headset is loose, so that the balls bump about and smash into the race during a bumpy ride. Since you hold the handlebars almost exactly straight during almost all of your ride, the balls hit the same spot over and over again. The risk is reduced if the bearing balls aren't actually spheres but little cylinders, which are also usually mounted at an angle, both of which spreads the impact energy.

You should frequently check whether your headset is adjusted properly. Stand behind the saddle, lean forward onto the saddle, engage the front brake with one hand, put the index finger of your other hand on the little gap where the top and bottom half of the top bearing join, and push hard against the brake. Your finger should not feel the gap shift at all. If there is the slightest movement you need to readjust it immediately.

If you lift the front wheel and turn the handlebars, and you feel a point of resistance where the fork appears to "snap" into the forward position, it's too late. The headset needs to be replaced. Since this is an expensive proposition, frequent checking is important. Don't ride with a broken headset, it makes it hard to ride in a straight line because the normal tiny handlebar movements become impossible.

See also an article on "Checking & Adjustment"

Checking the adjustment

Headsets break when the bearing balls crush the hardened surface of the bearing races. This happens when the metal of the races is too soft or the headset is loose, so that the balls bump about and smash into the race during a bumpy ride. Since you hold the handlebars almost exactly straight during almost all of your ride, the balls hit the same spot over and over again. The risk is reduced if the bearing balls aren't actually spheres but little cylinders, which are also usually mounted at an angle, both of which spreads the impact energy.

You should frequently check whether your headset is adjusted properly. Stand behind the saddle, lean forward onto the saddle, engage the front brake with one hand, put the index finger of your other hand on the little gap where the top and bottom half of the top bearing join, and push hard against the brake. Your finger should not feel the gap shift at all. If there is the slightest movement you need to readjust it immediately.

If you lift the front wheel and turn the handlebars, and you feel a point of resistance where the fork appears to "snap" into the forward position, it's too late. The headset needs to be replaced. Since this is an expensive proposition, frequent checking is important. Don't ride with a broken headset, it makes it hard to ride in a straight line because the normal tiny handlebar movements become impossible.

See Also an article on "Adjustment & Repair"

Adjustment and repair

If you can feel the upper bearing of the headset shifting during the above test, the bearing needs to be adjusted. Some headsets, such as older ones by Mavic, have a lock screw that needs to be loosened first, but normally it's a matter of tightening the nut that contains the upper bearing race against its lock nut. For this you need two appropriate wrenches; don't try to do this with regular household adjustable wrenches!

Unscrew the locknut, tighten the main nut until there is some resistance when turning the handlebars, then tighten the locknut. Tightening the locknut will loosen the main nut slightly, which is why you need to tighten it a bit too much at first. I usually have to repeat this a few times until I am completely satisfied. The handlebars should turn without resistance but pass the finger test, see above.

When I have to adjust my headset, I always use the opportunity to clean and re-grease all parts, both in the upper and lower bearings. A lot of dirt accumulates near the lower bearing, and some might find its way even into a properly sealed bearing.

Sometimes the result is the "indexed" mode where the handlebars seem to snap into the forward position. This is an indication that you waited too long. If you have plain bearing balls, there is one last chance to fix:

Bearing balls are either loose or in a cage (a small ring that holds all bearing balls). Since the indexing effect happens because all the balls simultaneously fall into the pits they have pounded into the races, it helps to change the number of balls. The best approach is to remove the cage if you had one, or put one in if you didn't. If you remove the cage, you must add more bearing balls - add balls until the bottom of the race is completely filled (liberally grease the race to hold the balls in place), then take one back out.

If you didn't have a cage and can't easily find one, it sometimes helps to remove a ball or two and hope that the balls float around enough to avoid alignment with the pits, but never fix a caged bearing by removing the cage without adding more balls. There simply won't be enough of them. Don't add fresh balls, replace all of them because the old balls will have been slightly flattened over time while the new ones are still round. Either way, these fixes are temporary and you should consider a new headset as soon as possible.


See also technical articles on "The Drive Train"

The Drive Train



* Brakes

* Gear Shift Levers

* Chainwheels, Cogs, and Chains

* Replacing a Chain

* Selecting a Gear Range

* Pedals

* Shoes

* Derailleurs

* Saddle

Brakes

Brakes are obviously the part of the bicycle that deserves the most attention. There are several different types:

* U brakes, named for their shape, are used on racing and most other road bicycles. There are various variants like centerpull brakes (Campagnolo Delta, an excellent brake but just too expensive), and sidepull brakes. The smaller they are the better they work because less material means less flex. There are cheap U brakes that would fit around your arm that you can watch bending when you brake. Good brakes are Shimano 105 and up, and any Campagnolo brake. Quick-releases help removing the wheel; Shimano integrates them into the brake and Campagnolo integrates them in the brake lever. You can ride Campagnolo levers with Shimano brakes but vice versa is difficult.

* Cantilever brakes are most often used on mountainbikes and hybrids whose tires are too fat to fit an U brake. I do not like cantilevers because they are hard to adjust and require continuous readjustment as the brake pads wear down. They tilt against the rim, which means that unlike U brake pads, cantilever pads do not touch the rim at a constant angle, so the angle must be readjusted frequently. Unfortunately, loosening the one single nut that secures the brake pad makes the whole assembly come loose and you have to adjust some six degrees of freedom all at once. Some people use spacers to adjust the pads while they press the spacers against the rim.

* Magura brakes replace cantilevers with two hydraulic cylinders that push the pads straight against the rim. Like regular cantilevers, they need a brake booster, a flat U-shaped piece of steel that connects both brake halves to keep them from pushing the fork apart. Maguras work really well; if they weren't so expensive I'd vote for throwing out all cantilevers.

* There are other forms, such as Shimano V brakes, but I have no experience with them. Hub brakes are often used on cheap bicycles; there are also high-quality hub and disc brakes that are useful for tandems which are much harder to stop. Hub and disc brakes have the disadvantage that they brake the hub, and a lot of force needs to be transmitted to the rim through the spokes.

There are a variety of brake pads that vary in softness. If the rubber compound is too hard, it doesn't brake well, especially in wet weather; if it is too soft, it wears down too quickly. Since rubber tends to get harder with time, brake pads should be replaced at least every couple of years. I prefer Campagnolo or Aztec. Some brake pads are longer than others, but I have not found this to make a difference. Some brake pads are designed for steel rims, but they don't make steel rims safe - never use steel rims because they are difficult or impossible to brake in wet weather. Good brake pads are not cheap, but this is about the worst place to save money!

Do not use ``safety levers'' that extend from the brake levers of cheap road bikes towards the stem (that holds the handlebars in the center). They aren't safe because they flex and brake poorly.

In road bike shift levers of the kind used for drop (racing) handlebars, the brake cables connect to the inside of the handle and run along the handlebars under the handlebar tape. The older type where the brake cable connects to the upper tip and arc up and then back down to the brakes are dangerous because you can accidentally catch the cable with your gloves, especially if you have aero (triathlon) bars.

For tips on installing and adjusting brake levers, see the chapter on handlebars.

See also an article on "Gear & Shift Levers"

Gear Shift Levers

Again, there are a number of different types:

* Down shifters are mounted on the down tube (that connects the front tube with the bottom bracket). They are on their way of becoming obsolete, but are still the cheapest option. They are inconvenient because they require reaching down, which is difficult to do when braking or accelerating hard or riding in difficult situations. A variant that is mounted on the stem is found on very old and cheap bicycles.

* Bar-end shifters are mounted at the ends of drop handlebars. I haven't used them much and find them less convenient than Ergopower and STI brakes because I don't often keep my hands at the handlebar ends where I can't reach the brakes. They are popular on touring bicycles.

* Campagnolo Ergopower is a system for drop handlebars that integrates the shifting levers with the brake levers. This means you can control everything without moving your hands. There is one lever mounted behind the brake lever that tilts sideways to shift down, and a thumb button on the inner side of the body to shift up. Up to three gears can be shifted down, and any number of of gears can be shifted up with one lever action. The levers become less noisy and hard with time. Both brake and shift cables run along the handlebar under the handlebar tape. This is the system that I prefer. They also come with Campagnolo's spare parts availability - it's not going to be a problem to buy and install a replacement spring three years from now, when Shimano won't even remember what they sold six months ago.

* Shimano STI is similar to Ergopower, but there is no thumb button. Up-shifting is done by pushing the brake lever sideways. This is why I prefer Ergopower - it makes me feel more in control because the brake lever doesn't go in all directions when I hold it with two fingers to be ready to brake. Also, STI has cables connecting to the inside tip of the lever that are not tucked safely out of harm's way like with Ergopower.

* Other types are available for mountainbikes. I have not used them.

On road bikes, the shifter cables run along the down tube, on the left side to the front derailleur and on the right side to the rear derailleur. There is a plastic insert under the bottom bracket that guides the cables. Cables must be bought to match the shifting system used. Ride-on makes special coated cables that run somewhat smoother than regular cables, but don't really justify the price. Normal cables should be oiled with Teflon oil (which doesn't gum up with age) before being inserted into the housing.

Shortening the housing is difficult and requires a special tool, or at least a sharp fine metal saw. The housing should be held by a vise. Saw it off very close to the vise grips, then file the sharp edges and smooth out the inner plastic tube. Use metal caps on the ends. Cables are usually too long; cut them with a sharp cutter and either put a cap on the end or solder the end (but don't use too much solder or they won't fit through the housing caps). Uncapped unsoldered cables fray.

See Also an article on "Chainwheels,Cogs & chains"

Chainwheels, Cogs, and Chains

In front, there are either two or three chainwheels. The innermost, smallest chainring is intended for spinning up steep hills. It's also called ``granny gear'', presumably to indicate who would need one. Me, I prefer two chainrings on road bikes because I don't have to worry about overshifting, because I have to worry less about extreme chain lines, and because I haven't yet met a mountain that was not easier to climb without a granny gear. The problem with the chainline is that a chain should not run from an inner cog to an outer chainwheel or vice versa.

There are cassettes with eight, nine, or ten cogs on the rear hub (for hub types, see the chapter on wheels). Cassettes with five to seven, and arguable eight, cogs are obsolete. At the time of this writing (2006), nine cogs are still available but fading, and people switch to ten. Ten-cog cassettes require a special narrow chain, and derailleurs and levers may not be compatible, so I recommend going with ten. In most cases, the number of cogs must agree with the type of shift levers; it cannot be upgraded without also replacing the shift lever. Usually cassettes from one vendor cannot be mixed with shift levers from another vendor. There are some exceptions, for example Sachs is said to work with Campagnolo, and Campagnolo sells replacement ratchets to convert levers.

Chains must be the single most neglected part of the typical bicycle. It seems that every other bicycle I see has not been lubricated for years. Unlubricated chains squeak pitifully, make pedaling much harder, and destroy chainwheels and cogs. The problem is that rust and other particles get between the bolts and sleeves of the chain and wear them down, so that the chain gets loose and hence very slightly longer. This means that the distance between two chain links no longer matches the distance between two chainwheel and cog teeth. When this happens only one link connects with a tooth, all others are loose because of the slack. This one tooth takes the entire force and gets worn into a ``shark fin'' shape. If this shape is pronounced enough, the chain won't even roll smoothly off the cog or chainwheel; instead the chain will be grabbed by the shark fin.

The insidious part of this is that you don't notice it until the cogs you use most are already destroyed. Replacing the chain will seem to make matters worse because now all links of the chain get hooked by all the shark fin teeth of the cog simultaneously, which will make the chain skip. This makes the cog unrideable. The only option at this point is to replace all the worn cogs together with the chain.

To prevent this from happening, it is important to lubricate the chain frequently, at least every three weeks or so, more often when riding in wet weather. Before lubricating the chain, it must first be cleaned with an old T-shirt. You can run the chain through the fabric, but it's really better to clean each link individually. It will only take a few minutes. You should also clean the cogs, chainwheels, and especially both pulleys in the rear derailleur. Then, lubricate the inside liberally, and run the chain through at high speed for some time. Then, wipe off all excess lube. This is important because only the lube inside the chain will do any good, the rest just attracts dirt and increases wear. Ride around the block and wipe off excess lube again.

There is much debate about the best chain lube. You can't go wrong with synthetic bicycle chain oil, perhaps containing suspended Teflon or other lubricating particles. Don't use regular (WD-40 or other) machine oil because its viscosity is too low to stay in the chain for very long, and don't use motor oil because motor oil is designed to work in certain (hot) environments only. Grease doesn't work too well because it won't reach the critical parts, you'll wipe off most of what you apply. This is even more true of wax. Don't use gasoline to clean your chain, it will remove the factory grease packing of the inner surfaces and you'll never be able to restore them sufficiently. Chains are not that expensive.

See also an article on "Replacing a chain"

Replacing a Chain

To replace a chain, push a pin out of the old chain and measure the new chain against the old to make sure it has the same number of links. If you have to remove links, remove them at the end without the bolt sticking out. If you have to break a chain with the intent to reinstall it, push one bolt towards the outer side of the bicycle until the link just barely holds together. Bend the chain to disengage the broken link. It's impossible to re-insert a bolt pushed out all the way. To install a chain, join the chain and push the bolt in until it is flush with the link plate, then push it back from the other side until it's as flush with the plate on that side as all the other links. Then, bend the chain sideways until it moves freely. A stiff link makes the chain skip when riding. You need a special chaintool for pushing bolts.

The chain length should be chosen so that all gear combinations are possible: if the chain is on the largest chainring and the largest cog, the rear derailleur should still have some play, and if the chain is on the smallest chainwheel and the smallest cog, it should not touch itself near the upper pulley in the rear derailleur. Of course you won't normally ride these extreme gears because of the poor chainline. If these conditions can't be met, consider changing the pulleys or chainwheels, or the rear derailleur capacity (i.e. use one with a longer cage). As a rule of thumb, the rear derailleur should be roughly vertical (both its pulleys are exactly below the axle) when the chain is on the largest chainwheel and the smallest cog.

In case of doubt I prefer a shorter chain because this increases its tension and makes it less likely to bounce and hit the chainstays (the frame tubes that connect the bottom bracket and the rear dropouts). On mountainbikes ``chain suck'' can become a problem when the chain bounces so much that it gets caught between the chainstay and the chainwheels. You can bolt little gizmos to the chainstay to prevent this, but I have seen these gizmos to cause more chainsuck problems than they solve because if the chain gets stuck anyway it gets stuck so tightly that it requires tools to make the bicycle ridable again. I am generally wary of little add-on gadgets.

See also an article on "Selecting A Gear Range"

Selecting a Gear Range

Bicycle newsgroups are awash with little programs to compute gear ranges, ``gear inches'', and stepping recommendations. I'll take the practical approach.

First, the ratio of front steps to back steps is important. The standard chainring set is 42-52 (teeth). I think of this as 24% step (1-(52-42)/42); if you shift on the big chainring the bicycle goes 24% faster at the same cadence (pedaling speed). The differences for the rear cogs is much smaller. For example, my usual cassette has cogs 13-14-15-16-17-19-21-23. This works out to 8-12% steps, so together with a 39-53 chainwheel set (36%) a front shift is equivalent 3 or more rear shifts. This is unusually large.

If the front-to-rear shift ratio is 1, you have too few distinct gears because for most front shifts there is an equivalent rear shift. A ratio of 0.5 is called ``half-stepping'' because front shifts insert another gear between most rear gears, at the expense of frequent double shifts. A ratio of 1.5 is called ``alpine''; it offers most of the fine gearing of half-stepping but extends the range at the ends, at the expense of even more shifting. My rather extreme ratio of 3 has a different goal; I rarely shift in front and use the small chainring for normal riding and climbing and the big chainring for high-speed downhill or flat-terrain riding.

Modern chainwheels and cogs cannot be combined arbitrarily, they are designed to work together to help the chain move from one cog to the next with small indents and protrusions that ``take over'' the chain and precisely chosen places. I usually pay little notice to this and put my cogs together any way I feel I need for the tour I have in mind, the loss of smoothness is negligible. Effectively, one chooses a rear cog cassette by choosing the extremes, such as 13-23 or 14-32. This decision depends on the type of riding:

* Choose a small range such as 13-23 for flat-terrain riding, and for group riding. When riding in a group, you can't control the speed unless you are in front, so finely stepped gears allow maintaining the optimal cadence for any speed.

* Choose a large range such as 14-30 for mountain climbing. Since the smallest chainring in a two-chainring set is usually 39, you need a large inner cog. I do not like three-chainring sets because they complicate shifting and spinning up hills at absurdly low speeds and high cadences are actually more work than to pump a higher gear.

* When I do a tour than involves both kinds of terrain, I often put together a cassette with small steps for the outer five cogs, like 13-19, and then continue with three extremely widely spaced cogs, like 23-26-30. This looks weird and the big gaps don't shift as smoothly, but I am at home in all terrains. Modern shifters are quite forgiving.

Cadence, or pedaling speed, is an important factor here. It is measured in revolutions per minute. Suppose you ride a road bike with a wheel circumference W of 2130 mm at cadence C, using a front chainring with F=42 teeth and a rear cog with R=17 teeth, your speed at C=100 is

(C * 60) * (F / R) * (W / 1,000,000) = 31.6 km/h

For mph, divide by 1.6. Beginners tend to ride at cadences of 60 or 70 rpm but you should aim at a cadence of around 90 or 100 rpm because it takes less strength and is easier on the knees. High cadences require clipless pedals (a term that means click-in pedals such as Time, Look, or Shimano SPD) because they allow you to apply constant force at all times, rather than stomping the pedal on the downward half of the circle. A bicycle computer that measures cadence is useful to train yourself to use a given cadence, but once you got used to it you won't need the cadence computer any longer.


See also an article on "Pedals"

Pedals

There are basically three types of pedals: pedals with clips and straps, ``clipless'' pedals that a cleat on the shoe clicks into, and pedals with neither.

Clips work best if they are made of plastic and have two prongs that the strap threads through, to prevent them from bending sideways. The strap should be twisted one full revolution inside the pedal to keep it from shifting. The lock at the strap end should be near the outer clip end, such that the other end of the strap points up, where it is easy to grab and tighten when riding. Tightening is unfortunately necessary frequently. It is also often necessary to untighten the strap manually before removing the shoe, especially if the shoe has a cleat with a horizontal groove that fits into the rear pedal edge. This, imho, makes clips dangerous because you may not get out in time in an accident.

Clipless pedals come in a variety of shapes. The two most popular ones are Time and Look, which require a large cleat that makes it hard to walk with the shoe, and Shimano SPD and Ritchey, whose cleats are recessed in the shoe to make it possible to walk normally. There are various clones and other more exotic systems. Racers prefer Time/Look because they hold the shoe more tightly while Shimanos seem to get more float and play (they call it ``freedom'') with every new generation.

Clipless pedals have two advantages that make them useful for anyone except the most casual riders:

* They allow applying force during the entire pedal cycle, especially while the pedal is moving up. You will develop an entire new set of muscles that help you pull up the pedal while you push down the other (learning this takes concentration on pulling; pushing works by itself). This improves speed and acceleration significantly. It takes some practice to also push or pull the pedal while it is at the top or bottom point of the cycle. The purpose of the exercise is a ``round'' pedaling cycle, which reduces knee stress, makes it possible to climb steeper hills, ride in tight groups, and generally improve performance.

* They also keep the rider in contact with the bicycle. Losing contact with the pedals when hitting a pothole or other obstacles, or when riding fast over cobblestones can easily cause a crash. If there is a crash, the pedals disengage practically automatically. There is virtually no danger of being hurt because the pedals fail to disengage. (Clips with tightened straps, on the other hand, can twist the ankle in nasty ways in a crash.) I have crashed several times in many different ways and never had a problem.

Personally, I prefer the Shimano/Ritchey system simply because I have clipless pedals on all my six bicycles and never ride without cleated shoes. Riding to a grocery store and amusing the audience by helplessly staggering about like a penguin because of the cleats is not my idea of convenience. If I raced competitively I would probably feel differently about this. Shimano sells racing cleats that solve much of the excessive sideways play problem.

Shimano pedals can wear out in two ways: the little nose under the front part of the cleat can be worn down, which makes it very hard to disengage from the pedal. This is dangerous but rare. More commonly the front U-shaped back-facing grip of the pedal gets worn from its U shape to a soft curve, which makes the pedal disengage unintentionally. In this case you can either replace the worn part, if you can manage to unscrew it after years of use, or buy new pedals.


See also an article on " Shoes"

Shoes

Shoes must fit the pedals. There are various kinds that accept cleats. They all have a very stiff sole with mounting sockets to attach the cleat to. The shoe should fit well, it should be neither too wide nor too narrow because the feet don't get much exercise while riding and can easily go numb if the shoe doesn't fit. Since good contact with the pedal is essential, they should fit snugly; choose one half size less than you would for a walking shoe.

Adjusting the cleat should be done very carefully because riding with the feet at an unnatural angle hurts the knee. Most people need to adjust the cleat so that the heel points in (of course not enough to touch the crankarms). Most people also prefer to mount the cleats just under the ball of the foot. This takes some experimentation and riding on the block to test adjustments. Don't be careless, knees take a long time to heal...

The soles of the shoes should not be flat but curved up near the toes because they can't bend during walking, being of tough carbon fiber plastic. The attachment point of the cleat must withstand quite enormous force. I have broken five out of six Shimano shoes at that point, three out of four Diadora shoes, and no Adidas shoes. Two of the Shimanos failed catastrophically, I ripped the cleat out of the sole while riding. This is dangerous. One of the Shimanos failed in another nasty way: since the top of the shoe was not very stable, twisting the foot would no longer disengage the pedal! This is even more dangerous. It seems that lately they got better, the newest model has held up for over a year. The Diadoras failed benignly, despite the broken sole they stayed ridable (but of course I replaced them anyway). My Adidases have survived much longer than any of the others and show no signs of failing, but they just recently lowered the quality (by removing padding) and increased the price, so they are no longer attractive. Today I ride cheap Performance shoes - all shoes seem to break after a while regardless of cost so I go with $40 specials.

See also an article on "Derailleurs"

Derailleurs

Most modern frames have a socket welded to their seat tube that the front derailleur is bolted onto. Most front derailleurs also come in a version that can be strapped to the seat tube if the socket is missing. The derailleur should be adjusted such that the cage is parallel to the chainwheels, and just barely clears the tips of the teeth of the chainwheels as it is shifted back and forth. There are two screws in the body of the derailleur that limit the movement of the derailleur. This prevents overshifting, which would throw the chain off the chainwheels.

Rear derailleurs are available with three different cage lengths (i.e. the distance between the pulleys). The length is called the capacity, and is measured in teeth difference: add the numbers of teeth of the largest chainring and the largest cog and subtract the numbers of teeth of the smallest chainring and the smallest cog. You can exceed the specified capacity of a rear derailleur by a couple of teeth but not more, or the chain will become stuck in unpleasant ways. For standard road bikes, my feeling is that you should stick with the shortest (racing) cage and adjust your chainrings and cogs because longer cages reduce shifting accuracy and make the chain bounce more easily on rough road surfaces. Many high-end rear derailleurs are available only with short cages.

It is absolutely critical to adjust the limit screws of rear derailleurs precisely. If the chain overshifts and falls off the smallest cog, it may block the wheel. If it overshifts at the other end, the derailleur might get caught in the spokes, which will probably crush or snap the derailleur in half and bend the dropout of the frame. A good mechanic may be able to bend the dropout back into shape (this requires special and very expensive frame alignment tools) but this is an excellent way of destroying frames.

Rear derailleurs must match the shift levers, or the gear spacing clicks built into the shift lever won't be translated to the correct cog distances by the derailleur. The result is a rattling noise in some, perhaps most, gears. There is an adjustment screw where the shifter cable enters the derailleur body. Adjust it so you can smoothly shift between the middle two cogs, then test with the whole range. After each adjustment of the screw, shift at least once. I have found it to be impossible to adjust until the chainline looks (and sounds) right and then do the next gear. Always keep shifting during adjustment. This is actually a simple procedure.

Don't bother with special sealed-bearing pulleys. Pulley friction is not a problem, and if the width of the new pulleys doesn't match the width of the original pulleys, the ends of the screws that hold the cage together might either hold the cage together poorly, or worse, stick out and catch the spokes with the usual catastrophic effects. Instead, clean the pulleys regularly, the accumulated gunk makes a much bigger difference. By the way, the back plate of the cage must be installed with the bigger end pointing down, or the chain will keep falling off the lower pulley.

See also an article on "Saddle"

Saddle

Saddles are important because if you choose the wrong one you'll be sore. Make sure it has a narrow nose and a standard-width back. If the nose is too wide it will rub the insides of your thighs. Avoid extra-narrow mountainbike saddles; they allow mountain bike riders to slip their weight easily behind the saddle on steep downhills but the loss of contact area can become painful quickly. There are wider saddles for women, whose pelvis is shaped differently.

Surprisingly, feeling the padding of a saddle for softness does not say much about whether the saddle is comfortable. Saddles usually consist of a hard shell, padded with foam with a flexible plastic cover. The thickness of the foam padding does not make a lot of difference for comfort because there are only two small contact points where bone meets the saddle. Even gel padding is only marginally better than foam. It's more important whether the plastic shell is completely rigid, which is not good, or whether it is flexible and held in shape by the two rails that the saddle is mounted on, especially if these rails are themselves flexible.

Some people swear by leather Brooks saddles, which work by the same principle except that the leather stretches more than plastic and so the rail mounting needs to be re-tightened occasionally. The leather needs to be rubbed frequently with oil at first so it is soft enough to change its shape to adjust to the shape of your pelvis, and must be protected from rain. Once you get past the initial months it's said to be the perfect saddle, but I prefer not to go through all the trouble.

One of the best saddles I have used is the regular racing Flite, which has next to no padding but a flexible shell and soft Titanium rails. I normally avoid the Titanium hype but this is a really useful application. Titanium is much softer than steel. Unfortunately you can't adjust the tension, so after a couple of years it sags and becomes unusable.

My favorite is the Selle Italia Turbo Matic 2, with its distinctive yellow/black rear end. It's the best of both worlds, and I have done many long tours with it.

The saddle height is very important. If it's too low, you have much less strength when pedaling, and if it's too high you'll rub your thighs sore. Adjust the height until you can pedal backwards with the heels of your shoes on the pedals, with fully stretched knees but still touching the pedal when the pedal is in the bottom position, without rocking your hips. The position must be exact to about five millimeters (1/5 inch). I prefer the standard angle where a bar laid on the nose and back of the saddle, parallel to the top tube, is horizontal, but some people prefer the nose slightly up or down.


See also an article on "Bicycle computers"

Bicycle Computers




* Riding computers

* Avocet vs. Cateye

* Heart rate monitors

* GPS Satellite navigation

* Taking Good Pictures




See also other technicle articles " Riding Ciomputers"

Riding computers

There are lots of bicycle computers available. They all offer

* Current speed
* Average speed
* Maximum speed
* Total distance: the distance since installing the computer
* Trip distance: the distance since pressing the reset button
* Trip time and wallclock time

This much is standard, but also consider the differences:

* Some computers continue computing average speed and trip time when stopping while others suspend. This means that average speeds are usually not comparable, at least in town.
* Some computers retain total distance, wallclock time, and wheel diameters when exchanging batteries while others don't.
* Mechanical stability and battery life is also an issue.
* A backlight is wonderful when trying to read the display at the end of the day in a campground.
* Cadence helps developing a proper pedaling speed. 100 rpm is much less tiring than the 70 rpm beginners prefer, and easier on the knees too. After developing the proper cadence the feature becomes useless and adds an extra wire.
* Wireless computers don't need a cable running down the fork but require a clunky sensor with its own battery. They also solve the problem of failing when the socket gets wet and short-circuits the connectors.
* Temperature is neat.
* Altitude is important when riding in the mountains or hilly terrain but it seems the technology is still immature, see below. I no longer use it; instead I now ride with a Garmin Legend GPS receiver strapped to my handlebars.
* Some computers support multiple wheel diameters, useful if the same computer is used on a road bike and a mountainbike.
* Does it use a reed sensor or a sensor ring? Reed sensors work with a small magnet clamped to a spoke. They are more sensitive to vibration and can drain the battery when the bike happens to be parked with the magnet next to the sensor. Sensor rings are more precise but require a longer cable all the way down the fork.

See also an article on "avocet-cateye-vdo-casio 600"

Avocet, Cateye, VDO, Casio



Here are my experiences with three high-end computers I tried, the Avocet 50, the Cateye CC-AT 100, and the VDO MC 1.0+. The Avocet 50 has been replaced with the 55 but I haven't seen one yet. All computers support altitude using a barometric pressure sensor.

* Avocet 50
works well when measuring altitude. It ignores small climbs under 10 meters, which makes it very precise. In the Alps and other mountains I have ridden in the displayed altitude matches the posted altitudes, and after returning to the starting point shows the original altitude to within a few meters. It seems unaffected by temperature and weather changes.

Unfortunately it eats batteries. It needs a new pair every six months, and loses all data when replacing batteries. After the batteries are about half-empty, altitude measurement becomes extremely erratic, once I climbed 200 meters while the bike was leaning against a wall. The casing is very brittle, when dropped it can come apart and scatter components everywhere, especially the batteries (they included two spare lids). And this is for the late production model, not one of the first which were completely unusable. I had mine exchanged four times on warranty.

The software is excellent, however. Every function can be reset separately. The combination of features on the display is dubious (why not current speed + trip distance in the same mode?) and it ignores button presses in quick succession, but basically it's well-designed. It has no temperature and no backlight. There is a cadence option.

* Cateye CC-AT 100
It's ugly and clunky, and the altitude measurement is broken. The altitude display jumps by 5..7 meter every few seconds, less often in the "fixed" newer model that also has a trip altitude function. These errors are accumulated in the total altitude gain, which makes for very impressive totals even in perfectly flat terrain. However, with a fresh battery these problems mostly disappear, then it again becomes more unreliable as the battery wears down.

The user interface is stupid, one button is largely unused while the other must be pressed for two seconds to access important submodes. The combination of data on any given display is better than on the Avocet though.

It is also mechanically stable, unlike the Avocet. It does stop working in heavy rain. Counts can only be reset all at once. It has temperature and backlight, but no cadence option. Like the Avocet it doesn't support 24-hour wallclock mode.
* VDO MC 1.0+
This is my newest computer, and it beats the other two hands down. Finally, a reliable altimeter, and it has all sorts of extras like inclination, top and average altitude, average climb, temperature, two bikes, and so on. It also shows lots of data on the screen, and has three buttons to cycle through the alternative fields - one for the usual distance and max/average speed mode, one for odometers and clock, and one for the altimeter modes; 16 modes total. It's very easy to use.

It's also wireless. That's great because rain can't stop it, but it's sensitive to stray EM fields. Recently it counted two kilometers while in my pocket in a computer store, and four kilometers in a subway near where I suppose the brakes are. Another minor disadvantage is that you need to press a button to get it out of sleep mode.
* Casio ALT-6000
This is not a bicycle computer, it's a watch. Actually it looks like a crashed flying saucer. I bought it to see if there is a reliable way to get altitude readings on a tour. It's a failure.

It shows both barometric pressure and altitude, numerically and in a little graph. Pressure readings work fine in a shop window but when you actually wear it the graph dissolves into a cloud of disconnected pixels. The altitude graph is sort of fun to watch, but serious measurement errors throw off the autoranging. Its long-term history may have some anecdotal value. It has a terrible user interface and forgets the graph when switching modes. It also shows the temperature average between your wrist and the back side of the moon. Or something.

Don't buy this. It's an expensive useless toy for kids and has no real value.
* Garmin Legend, Garmin Vista
Lovely, solves the problem, although at a high price. See below.

The first three computers need to have their wheel diameter set precisely so they know the distance that corresponds to one wheel revolution. To measure this distance, make sure your front wheel is installed with the correct tire, and pump it up to the desired pressure. Mark a spot on the wheel with chalk and align it with a mark on the floor. Sit on the bike and ride forward in a straight line for one full wheel revolution, and mark the spot on the floor under the chalk mark. Measure the distance between the two marks on the floor to the closest millimeter, and enter it into the computer. Some computers require some calculation instead of accepting the distance directly.

Garmin now has a GPS bicycle computer named the Edge 205. I haven't used it because although it could be the first of an exciting new species of bicycle computers, it doesn't seem mature. It's bulky, expensive, and lacks the most important feature of a GPS receiver, mapping. It may have some uses in training for athletes.

See also an article on "heart rate Monitor"

Heart rate monitors





Regular computers measure bicycle statistics; heart rate monitors measure your pulse. While this seems like a very marginal option, strictly for professional athletes, it actually tells more than the current speed of the bicycle. I am familiar with the heart rate monitor made by Polar. It consists of a chest belt and a display unit that can be installed on the handlebars or worn at the wrist. The connection is wireless.

The heart rate is surprisingly variable. It can jump up and down rapidly as exertion changes. It can jump from 90 to 180 or vice versa in much less than a minute - and it takes longer after a long ride. Watching the heart rate allows the rider to keep his pulse in a safe zone and avoid extremes. For example, I avoid exceeding 160 beats per minute in flat terrain because I wouldn't be able to keep it up for an entire ride, while exceeding 190 is not unusual for short bursts of speed. Just rolling along at 120 or 130 is relaxing. On a long tour I start with heart rates around 150, and after a week I barely exceed 110 even uphill. I monitor my heart rate much more closely now than my speed because it lets me plan my rides better.

Of course I am talking about 100+ km rides. There is not much point in wearing a heart rate monitor when riding to the grocery store around the corner. But I do recommend them to long-distance riders. On a recent 300km ride on a single day I adjusted my speed to my heart rate, starting with 120 bpm. I had to revise this later until my target rate was 150 bpm near the end of the ride. I have done long rides before but never felt so confident that I could finish the ride safely.

I recently (5/2000) got a new Polar M52 heart rate monitor that also derives fitness information, calory measurements, and training schedules from heart beat variability. It is a wonderful toy. I can't verify the calory estimates but they seem plausible. The fitness test seems dubious though - I have improved from 52 to 57 within two weeks of moderately hard riding, much faster than the manual claims is possible, with an intervening result of 44. (The numbers must be looked up in a table.) A friend got 72, way off the scale.

It has two annoying flaws, in addition to a chaotic user interface: training cannot be stopped and resumed for a pause because stop mode quickly times out and aborts the measurement, and although the belt-to-computer signals are encoded the code lock is inevitably lost and is pretty much impossible to reacquire, which makes the computer pick up signals from other people. Occasionally the heart rate display is wildly inaccurate for short times. When the chest belt battery is near the end of its life, you get absurd readings like 220 beats (my heart never goes much above 200 even in absolutely extreme situations). You can exchange the battery in the display unit, but the chest belt must be sent in; it's sealed. It's not very practical to cut open the belt to replace the battery; the battery is soldered to the board and the belt is difficult to re-seal (see picture to the right). Polar now offers a belt with a replaceable battery.


See also an article on "GPS Satellite Navigation"

GPS Satellite Navigation




I have recently (August 2007) replaced my Garmnin etrex Legend GPS receiver with a Garmin etrex Vista HCx. GPS means Global Positioning System, a network of 24 satellites that broadcast signals that permit computing the position of the receiver to within 100 meters in theory and between 5 and 10 meters in practice. The H in HCx is critical: it means that the device has the newer SirfStar chipset, which is much faster finding a fix, and finds a fix even in difficult situations where the non-H version gives up after half an hour. Don't buy the old model, it's very frustrating in comparison to the HCx! mounted Garmin GPS, 9.8k

GPS receivers got a lot better. With my old Garmin 38 I spent half the time fantasizing that a piece of paper with the words "Poor GPS coverage" written on it would make a very cost-effective replacement for the receiver - lightweight, no batteries, with most of the functionality. The Garmin Vista HCx is the current generation which is far more reliable. After turning the receiver on, it finds an initial fix in less than a minute, and then it's quite good at staying syncronized. Trees, buildings, and other obstacles don't block satellite reception as easily as the older non-HCx versions.

The etrex also stores maps; I have the Europe city street maps loaded in mine and I love it. Very expensive though, and installation is infuriatingly braindead. You must create an account on the Garmin web site, type in all sorts of private information (of course I typed in garbage, including a bogus email address), and numerous poorly identified serial numbers and bonus codes. And you must have Windows, if you have a Mac or Linux, like I do, you lose.

Once installed, the software is quite good. It can also do turn-by-turn routing: you enter an address or click a location on the map, and the device gets you there. Before and at intersections it tells you where to go. It can be set on bicycle mode, but that doesn't work too well - it avoids freeways, but I live in the old Berlin downtown with its many one-ways, blocked roads, and mandatory turns, almost all of which don't apply to cyclists, but the Garmin map doesn't know that and suggests fantastically complicated detours. Now I know how car drivers must feel here...

Garmin GPS receivers allow keeping a track log, basically painting a line on the map for the route taken. That requires that it's turned on all day; I use about one NiMH battery charge per day. In 2002 I recorded an entire tour with 500-meter accuracy, and in 2004 a 1600-km tour with 1.5 and 0.5 km accuracy. I use the handlebar mounting bracket. Really nice. That was with an older Garmnin Legend; the Vista HCx can store tracks on a flash card and should have a much higher capacity. I didn't try it yet.

Once again, mapping GPS receivers are great, but DO NOT buy one that doesn't have the SirfStar chipset!

See also an article on "Taking A good picture"

Taking Good Pictures




When choosing a camera, get one that does everything by itself and fits into the waist pouch. Wide-angle lenses are best. Don't bother with replaceable lenses, no matter of how you feel about point-and-shoot cameras. Make sure you have a spare battery. Do not take them to the beach if there is a risk of sand or water getting into the camera. I used to use a Nikon AF-600 with the Panorama switch glued in the off position, but today (2006) I use a digital Canon S80 and I can't believe that I ever put up with a pre-digital chemical camera. I love my Canon.

You'll enjoy the pictures only if you take some care composing them. It is impossible to take a picture of a landscape panorama, for example - all you'll get is a picture that is divided into a blue and a green half with some indiscernible tiny detail at the boundary. Here are some rules I use:

Mt. Marmolada, 8.6k

* Don't make postcard pictures. The pictures should help to remember the trip, not impress your friends. Prefer pictures of things of personal significance. A picture of your hotel room will prove more valuable than one of the Eiffel tower.
* Make sure any picture has both foreground and background. The foreground element should have an identifiable size to give a reference point - a person or bicycle will do, perhaps plus a tree or street light.
* There should be an element that connects foreground and background to give a sense of perspective and depth. A road or the edge of a forest work fine.
* There should be a focus element in the center of the picture. If there are two interesting elements make two pictures instead of combining them into one with a big void in the center.
* The foreground should be darker than the background to increase the depth impression.
* Choose a point of view when the sun is to one side, not behind or in front of you (unless you want to make an effects shot); the shadows give structure to flat surfaces.
* If the scene has some very bright spots, point the camera to an evenly lighted area and let it do its light measurement there. Most cameras do the measurement when the button is pushed halfway in and takes the picture when it is pushed all the way in. Otherwise the picture will be all dark and mushy except for the bright spot. If you insist on using an old-fashioned chemical camera, the lab will mercilessly overexpose dark pictures to reach an average light level.
* It's extremely hard to make a picture that shows the steepness of the road you are on. Don't even try to point the camera down or up to show the incline; keep the view axis horizontal.
* Another tip for chemical cameras: the first few pictures of a roll of film should not have bright colors or unusual brightness because the lab uses them to calibrate the development machinery. Also, the first and last picture are often lost or taped over by the lab. Quaint.

The picture above is an example from my Marmolada tour. There are riders in the foreground who give a size reference, a road distorted by perspective, dark trees in the foreground with a tall one in the center, and a brightly lit mountain in the background that almost seems to float. It happens to be a downhill but one can't see that.

I have replaced my old chemical camera with a digital still camera (Canon S80, replacing an older S40 and a primitive Sony). The choice between chemical and digital is not one of storage medium. The digital camera is a completely different device because it encourages taking snapshots at any opportunity. I now take at least five to ten times as many pictures because they are so wonderfully easy to take, review, delete, store, and process. No more guesswork, waiting for prints, extra expense for additional prints, and stacks of paper printouts. Bring one to a party and everybody starts posing and having fun. Digital cameras are a true revelation.

Professional photographers, and aspiring amateurs, will tell you that point-and-shoot chemical cameras and digital cameras cannot take serious pictures. This may be true if you are a professional photographer but it is nonsense for people like me who want to take high-quality snapshots with little preparation and posing. I have digitized well over a thousand old chemical photos, and let me tell you, chemical photography is the pure horror. Film ages, gets scratched by the camera, the lab, and in storage, and it inevitable attracts dust that gets embedded in the emulsion. Another thing I never stopped to think about: chemical cameras cannot compute a white balance, so most pictures will have incorrect blue (sunlight) or yellow (incandescent light) tints. Take a close look at older film and you will be shocked, and amazed how the lab could possibly get decent prints out of such information garbage.

(That said: of course I realize that film has a higher, S-shaped dynamic range while digital cameras have a narrower ramp range, so shadow and highlight detail gets lost more easily. Film also has a somewhat larger color gamut, although it may discolor with age while digital images never change. However, this is getting us into the domain of professional or semi-professional photography, where light composition is an art, and it doesn't invalidate my statements about nonprofessional photography.i And I notice that professional reporters have gone digital too, and modern digital SLRs can make stunning pictures.)

Take my advice: do not use a professional, adjust-everything-manually camera if you just want to take snapshots. My Canon does have manual modes and I have beautiful night shots with them, using a tripod of course, but much of the time you'll just want to whip out the camera, take a picture, and ride on. In such a situation your pictures will be worse with manual adjustment unless you are a whole lot more meticulous and willing to spend much time to prepare each shot and adjust the camera than I am. If you must stick with chemical cameras (they are still cheaper), use a fully automatic camera with a good lens; if you want to get good pictures get a digital camera with a good and not too small lens! I am serious. You can still make mistakes with a digital camera, of course, but at least you'll see your mistake immediately, and once taken a picture never degrades or gets scratched. And, to repeat this important point, a good large lens is much more important than whether it has two or ten megapixels. Don't even think about the toy cameras built into most modern cell phones, and their megapixel claims, the lenses and CCD chips are a joke.

I used to have a Sony F55E but the swivel lens killed the printed cable inside. My new Canon is far better than any Sony I have checked out. Also, I am truly tired with Sony's overpriced proprietary memory sticks, and I wanted CF cards. Half the price per byte, and available with eight times the capacity. Sony is off my list. Anything that needs xD cards too. Check out www.dpreview.com for good reviews.

(Silly digital camera trick of the week: they are sensitive to infrared light, so you can use them to test IR remote controls and IrDA ports.)


See also an article on " Bicycle Clothes"