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Tires /
Brakes / Wheels /
Cables /
Chains /
Headset / Noise /
Other Troubles
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.
Tires
Before 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.) Under inflated 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.
Brakes
Stand 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.)
Wheels
The 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.
Cables
The 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.
Chains
The 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 chain rings 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.
Noises
If 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 Troubles
When 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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