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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 tube, 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 tube 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.
Figure 8.
WaRninG
PatChinG a tUBe is an emeRGenCy
RePaiR.
If you do not apply the patch correctly or apply
several patches, the tube can fail, resulting in
possible tube failure, which could cause you to
loose control and fall. Replace a patched tube
as soon as possible.
schrader valve
Presta valve
valve stem
locknut
