OK, the season is going and you've got your bike
all tuned up. If you haven't then please refer to the "Pre-Season
Check" article. One of the most important part of your bike is the
tires. They are also the part that are thought of the least when checking
the bike over. So here is some information that should be helpful.
Tire pressure:
Tire pressure is very important as it can
influence not only how the bike roles but how it handles on a track.
There really isn't a "correct" tire pressure as each racer
finds something that works for them, however here are some guidelines.
The higher the pressure, the better the bike will roll, however the bike
won't absorb the bumps as well. If the pressure is too low, the bike will
be harder to pedal and as you lean or go into a corner the tire can
"roll" on the rim, making it harder to control in a corner. Low
pressure will also make the tube more likely to be "pinched" between
the tire and rim, resulting in a puncture. For heaver riders, 150 pounds
or heaver, a tire pressure of between 35 psi and 70 psi is where the tire
should be. Most riders in this category will use between 50 and 60 psi.
For younger riders, especially if they run the "skinny" wheels,
the tire pressure should be between 60 psi and 90 psi. Tire pressure
should be checked every couple of races and in fact the "skinny"
tires should be checked before every race as they hold less air and even a
small loss of air can result in low tire pressure.
Tire tread:
Tire tread is very subjective and to be truthful
most tread patterns work. Large knobby tires will grip well if the dirt
is soft, which isn't encountered that often, but it takes more effort to pedal
the bike and the bike won't roll easy. A tire with little or no tread
will roll easier, but may not grip well. Younger riders can get away with
limited tread on most track surfaces as even the slightest amount will grip
well. For older riders, a "low profile" tread will be a good
choice. Tires by Supercross, Maxis, Intense, and Kenda offer a variety of
tread patterns and sizes to choose from.
Tire wear:
The rear tire will be the one to wear down after
use mainly because it's on the drive wheel. Also the break on all BMX
bikes stops the rear wheel so skidding is common. If the tread is visibly
worn, the tire could lose traction in a corner and should be replaced. Tires
are one of the least expensive part on a bike so don't skimp on the tires.
Tubes:
Tubes get holes, it's a fact. They are thin
and we are riding on dirt, which may contain sharp rocks, glass (hopefully not)
and thorns. Patch kits are available, however tubes don't cost much
(usually less then $10.00) and are easier and faster to replace then patch.
Always have at least two tubes on hand at races, even if you don't know how
to change them. It's not much fun not being able to race because of a
flat and you should be able to find someone at the track who can help you
change a tube if you don't know how, but you may not be able to find a tube.
Next time we will go over a discussion of gears.