Canyon Mountain bike Manual page 37

70 WHEELS TYRES AND INNER TUBES
THE WHEELS - TYRES,
INNER TUBES AND AIR
PRESSURE
The wheels of your Canyon create the contact to the
road or track you are riding on. They are subject to
considerable stress through the weight of rider and
baggage as well as through bumpy road surfaces
or ground. Although wheels are manufactured with
great care and delivered accurately trued, this does
not prevent the spokes and nipples from losing a lit-
tle tension on the first kilometres. For this reason it
may be that the wheels must be trued up as early as
after you have run them in over about 100 to 300 kilo-
metres (60 to 180 miles). Check the wheels regularly
after you have run them in. It will rarely be necessary
to tighten the spokes.
The wheel consists of hub, spokes and rim. The tyre
is mounted onto the rim so that it encases the inner
tube. There is a rim tape running around the base of
the rim to protect the sensitive inner tube against the
spoke nipples and the edges of the rim base, which
are often sharp.
If you want to replace a tyre, you need to consider the
actual size of the old tyre. It is marked on the side of
the tyre. There are two designations, the more pre-
cise of which uses millimetres. The number sequence
57-559 means that the tyre is 57 mm wide when fully
inflated and that it has an inner diameter of 559 mil-
limetres. The other designation for this tyre reads
26x2.25 which refers to inches. By choosing a bigger
tyre you risk that the tyre drags along the fork or the
rear frame. Therefore, please mount a tyre of identi-
cal dimension.
Wheel
Dimension and air pressure range of the tyre
Rim tape in the rim
If you mount a new tyre with another size
than the standard tyre mounted, it might
be possible that the clearance between the front
of your shoe and the wheel will be reduced when
you ride at reduced speed. During compression of
the suspension system a wheel can get jammed,
as well. Risk of an accident!
Tyres have to be inflated to the correct air pressure in
order to work properly. Adequately inflated tyres are
also more resistant to flats. An insufficiently inflated
inner tube can easily get pinched ("snake-bitten"),
when it goes over a sharp kerb.
The air pressure recommended by the manufacturer
is given on the side of the tyre or on the type label. The
lower of the two pressure specifications makes for
better cushioning and is therefore best for off-road
cycling. Rolling resistance decreases with increasing
pressure, but so does comfort. A high tyre pressure is
therefore most suitable for riding on tarred roads and
smooth paths.
Inflation pressure is often given in the old system of
units, i.e. in psi (pounds per square inch). The table
gives the most common pressure values in terms of
three systems.
The tyre and rim alone are not able to hold the air. Ex-
cept: Tubeless tyres with mountain bikes. Therefore,
an inner tube has to be placed inside the tyre to retain
the air pressure. The tube is pumped up via a valve.
Canyon bikes are equipped with Sclaverand or race
valves, which are meanwhile used on nearly all types
of bikes. This valve is provided with a plastic cap to
protect it from dirt.
Riding with too low air pressure may make
the tyre come off the rim.
Tyres allowing an inflation pressure of five
bars or more have to be mounted on hook
bead rims, identifiable by the designation "C".
TYRES AND INNER TUBES WHEELS
Sclaverand valve
Unscrewing the plastic cap
psi bar kPa
30 2.1 210
40 2.8 280
50 3.5 350
60 4.1 410
70 4.8 480
80 5.5 550
90 6.2 620
Air pressure in psi, bar and kPa
Never inflate your tyres beyond the maxi-
mum permissible pressure, otherwise one
of them might burst or come off the rim during the
ride. Risk of an accident!
If you mount a tyre which is wider than the
standard tyre mounted, the tyre may drag
along the fork crown with a completely com-
pressed suspension fork.
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