Ask your dealer to recommend the best tire pressure for the kind of riding you will most often do, and have the dealer inflate
your tires to that pressure. Then, check inflation as described in Section 1.C so you’ll know how correctly inflated tires should look
and feel when you don’t have access to a gauge. Some tires may need to be brought up to pressure every week or two, so it is
important to check your tire pressures before every ride.
Some special high-performance tires have unidirectional treads: their tread pattern is designed to work better in one direction
than in the
other. The sidewall marking of a unidirectional tire will have an arrow showing the correct rotation direction. If your bike
has unidirectional tires, be sure that they are mounted to rotate in the correct direction.
2. Tire Valves
There are primarily two kinds of bicycle tube valves: The Schrae
der Va
lve and the Presta Valve. The bicycle pump you use
must have the fitting appropriate to the valve stems on your bicycle.
The Schraeder valve (fig. 18 a) is like the val ve on a car tire. To inflate a Schrae der valve tube, remov e the
valve cap and clamp the pump fitting onto the end of the valve stem. To let air out of a Schraeder valve, depress
the pin in the end of the valve stem with the end of a key or other appropriate object.
The Presta valve (fig. 18b) has a narro wer diameter and is onl
y found on bic ycle tires. To inflate a Prest a
valve tube usi ng a Prest a h eaded bic ycle pump, remov e the valve cap; unscre w (co unterclockwise) the valve
stem lock nut; and push down on the valve stem to free it up. Then push the pump head on to the valve head, and
inflate. To inflate a Presta valve with a Schraeder pump fitting, you’ll need a Presta adapter (available at your bike
shop) which s crews on to th e valv e stem o nce you’ve freed up the valve. T he adapt er fits into the S chraeder
pump fitting. Close the valve after inflation. To let air out of a Prest a valve, open up the valve stem lock nut an d
depress the valve stem.
WARNING: W e high ly rec ommend tha t y ou c arry a sp are inne r tube when y ou ride y our bik e.
Patching a tube is a n emergency repair. If y ou do not apply the patch correctly or a pply several
patches, the tube can fail, resulting i n possible tube failure, which could cause you to loose control and
fall. Replace a patched tube as soon as possible.
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