GT Grade, Руководство пользователя

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PART 1
4.F - Bicycle Suspension
Section 4. Tech
GT Bicycle Owner’s Manual
CAUTION
Pencil type automotive tire gauges can be
inaccurate and should not be relied upon for
consistent, accurate pressure readings.
Instead, use a high quality dial gauge.
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 Schrader Valve and the Presta
Valve. The bicycle pump you use must have the
fitting appropriate to the valve stems on your
bicycle.
The Schrader valve (fig. 18) is like the valve on a
car tire. To inflate a Schrader valve tire, remove
the valve cap and clamp the pump fitting onto
the end of the valve stem. To let air out of a
Schrader 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. 18) has a narrower
diameter and is only found on bicycle tires. To
inflate a Presta valve tire using a Presta headed
bicycle pump, remove the valve cap; unscrew
(counterclockwise) 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 Schrader
pump fitting, you’ll need a Presta adapter
(available at your bike shop) which screws on to
the valve stem once you’ve freed up the valve.
The adapter fits into the Schrader pump fitting.
Close the valve after inflation. To let air out of a
Presta valve, open up the valve stem lock nut
and depress the valve stem.