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Bike Fitness: Keeping Your Bike in ShapeBy Rich Gibbs
Our preparation for the AIDS Ride focuses a lot of attention on developing our physical fitness as Riders: we have a training manual, group training rides, and even Training Expos! But it's also important that we keep our bikes in good shape, for reasons of comfort, efficiency, and safety. This article will describe some basic checks that you can easily make to help ensure that your bike is in good condition, and stays that way.
TiresBefore each ride, you should check the inflation pressure in your tires, and pump them up if required. (The recommended inflation pressure should be shown on the tire's sidewall.) Underinflated tires increase rolling resistance (who wants to work too hard?), and are more prone to pinch ("snakebite") flats. Use a good floor pump and a pressure gauge. The air dispensers at gas stations are designed to fill automobile tires, which use a large volume of air at relatively low pressure, and their pressure indicators are often very inaccurate.
Also check the tire for cuts or imbedded objects in the tread or in the sidewall. Tires with significant cuts, or with the fabric plies visible, should be replaced.
BrakesStand over the bike, and try to roll it forward while applying each brake in turn. You should be able easily to lock the wheel (so that it skids) with the brake, without having the brake lever reach the handlebar. If you can't do this, get your brakes repaired and don't ride the bike. Also check that, if your brakes have quick releases, they are closed. Check the brake shoes for embedded objects. If necessary, brake shoes and the braking surface of the rim can be cleaned with isopropyl (rubbing) alcohol to remove grease.
(If there are clunking noises when you check the front brake in this way, it may indicate a problem with your headset. Have your bike shop check it.)
WheelsThe first thing to check is that the wheels are securely attached to your bicycle! Make sure that the quick-release skewers are properly closed; it should take a noticeable amount of force to close the lever (enough to make an imprint of the lever on your palm). If your bicycle uses nuts to hold the wheels on, make sure they are properly tightened.
Lift each wheel off the ground, and rotate it. It should spin freely, with little friction, without rubbing against the brake blocks or anything else. If the wheel binds as it turns, or if you feel or hear a gritty sensation, your hub bearings probably need to be serviced. Watch the wheel as it turns, to make sure it is at least roughly true (round!). Wobbly wheels can result from loose or broken spokes, and should be serviced -- they will tend to get worse at an increasing rate if left to their own devices. Look at your rims, too. Cracked or dented rims need to be checked, and repaired or replaced as required.
CablesThe brakes and gears on your bike are operated by cables. Check the cables and their housings periodically for signs of fraying, rust, or other damage, and replace them if needed. A broken derailleur cable is an easy way to turn your 16- or 24-speed bike into a 2- or 3-speed, and a broken brake cable can be very dangerous.
ChainsThe chain transmits power from the pedals to the rear wheel to make you go. It is also very exposed to the elements, and to dirt and grit from the road, which tend to adhere to the chain because of the lubricant used on it. This combination on your chain works like liquid sandpaper on both the chain itself and your chainrings and cogs. Keep the chain clean, and these parts will last longer; as a bonus, working on your bike (for example, to fix a flat) will be a lot less messy.
You can clean a chain by removing it from the bike with a chain tool, and soaking it in a degreasing solvent. An old toothbrush can be useful to remove stubborn muck. Alternatively, there are small chain cleaning devices (made, for example, by Pedro's, Park Tool, and Finish Line) that will clean the chain on the bike. These work reasonably well if used regularly.
The chain also needs to be lubricated regularly. Your bike shop has a variety of chain lubricants available; all of them work, although some are more suitable for certain types of riding conditions than others. As a rule of thumb, "dry" or waxy lubricants work better for dry conditions, and more oily lubricants last longer when it is wet. Be sure to follow the directions on the package.
A new chain measures exactly 0.5 inch between rivets, measured center to center, so 24 links are exactly one foot. Chains don't stretch, in the sense that a rubber band does, but become elongated due to wear around their rotating parts. The best way to check a chain for wear is to measure 24 links with a good ruler. If they measure between 12 and 12 1/16 inches, the chain is OK. At 12 1/16 inches, the chain should probably be replaced, to avoid excessive wear on other components. If the length gets to 12 1/8 inches, the chain is definitely worn out, and may also have worn out one or more cogs.
NoisesIf your bike starts to make a strange noise while you are riding it, don't just ignore it. Most clicks, squeaks, and other noises are not serious and are easily fixed, but taking chances is silly. Have an experienced person check it out.
Other TroublesWhen you check over your bike, be on the lookout for any cracks or other obvious signs of deterioration in metal parts, especially the frame near tube junctions, and the handlebars. Particularly in aluminum parts, these can be warning signs of advanced metal fatigue.
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