INFL ATING YOUR HUMMINGBIRD’S
T YRES WITH THE PRESTA VALVE
Check The Valve & Deflate The Bike Tyre
Find the valve and remove any dust-cap.
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CHECK THE VALVE
If the presta valve hasn’t been opened for a while release a short hiss of air
to check it’s not stuck. The same process, holding the valve open longer,
deflates the bike tyre.
PRESTA VALVE
A presta valve is locked with a tiny acorn nut, unscrew this before you
inflate a bike tyre and press the stem down to release air.
CONNECT THE PUMP
The hose or pump connection may screw on or press on. Some push fit
connections lock with a cam lever. To check the correct operation of the
connection look at the rubber washer and move the lever back and forth.
The the ‘locked’ position squeezes the washer, the ‘on-off’ position lets the
washer relax. The rubber washer in a pump connector wears out with use.
It needs to be replaced when it stops gripping valves to give an air-tight
sea.
INFL ATE THE T YRE
If your pump or hose has a push fit, press the connection on parallel to the
presta valve to avoid releasing air or bending the presta valve stem.
Fully open and fully close the pump with each stroke. It’s important to
press the piston right to the end of it’s travel to force air into the tyre. If
you stop too soon the air in the pump will tend to compress rather than
flow into the tyre.
