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Inflation pressure is often given in the old system of units, i.e. in psi
psi
bar
kpa
(pounds per square inch). The table gives the most common pressure
30
2,1
210
values in terms of both systems (a).
40
2,8
280
The tyre and rim alone are not able to hold the air. Therefore, an inner
50
3,5
350
tube has to be placed inside the tyre to retain the air pressure.
60
4,1
410
70
4,8
480
VALVES
80
5,5
550
a
There are three valve types in general use on city and trekking bicycles:
1. Sclaverand or presta valve (b): This valve is nowadays used on
2. Schrader or american valve (c): This is an adapted car tyre
3. dunlop or woods valve
b
All valve types come with a plastic cap to protect them from dirt.
The Schrader and dunlop valves can be inflated with a suitable pump
directly after removing the protective cap.
With presta valves you first have to undo the small knurled nut a little
and depress it carefully until air starts to escape. Check the valve core
is tightened and seated in its stem, otherwise air may slowly leak out.
Do not forget to tighten by hand the valve nut after inflating.
Tyres with Schrader valves can conveniently be inflated at car filling
c
stations with a compressed air dispenser. The same applies to dun-
lop and presta valves fitted with a special adapter. A compressed
air dispenser must be used very carefully in short bursts as you may
otherwise overinflate the tyre and make it burst. To let out air, press
the needle in the centre of the Schrader valve or the knurled nut of the
Presta valve (e).
In the case of the dunlop valve unscrew the knurled nut until air comes
out of the valve. Retighten the knurled nut subsequently. Normally, you
have to inflate the tyre completely.
d
It can be hard to inflate tyres to the necessary pressure by using hand
pumps. It is much easier with a track pump equipped with a pressure
gauge (f).
64
almost all types of bicycles. It is designed to withstand extremely
high pressures.
valve.
(d)
– the usual valve.
G
Replace tyres with a worn tread or with brittle or frayed
sides. Dampness and dirt penetrating the tyre can cause
damage to its inner structure. The tube might burst. danger
of an accident!
G
Treat your tyres with care. never inflate your tyres beyond
the maximum permissible pressure, otherwise they might
burst or come off the rim during the ride. danger of an ac-
cident!
G
Tyres allowing an inflation pressure of 5 bars or more have
to be mounted on hook bead rims, identifiable by the desig-
nation "C". If you are in doubt or if you have any questions,
then contact your WHEELER bicycle dealer.
G
If you mount a tyre of another size than the standard one,
it may be that the tyre will rub against the suspension fork,
the mudguard, the brakes or other components and sus-
tain damage. This can even lock up the wheel. When buying
tyres, ask your WHEELER bicycle dealer for advice.
A
Always ride your bicycle with the prescribed tyre pressure
and check the pressure at least once a week (g).
I
observe the maximum pressure value of the rim. The pres-
sure is dependent on the tyre width. You can find the values
in the operating instructions of the rim or wheel manufac-
turer
(h)
on the enclosed CD. If you are in doubt or if you
have any questions, then contact your WHEELER bicycle
dealer.
e
f
f
g
h
65
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