The Wheels - Tyres, Inner Tubes And Air Pressure - Canyon road bike Manual

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
23-622 means that the tyre is 23 mm wide when fully
inflated and that it has an inner diameter of 622 mil-
limetres. By choosing a bigger tyre you risk that the
tyre drags along the fork or the rear frame. Therefore,
please mount a tyre of identical dimension.
Wheel
Tyre size
Rim tape in the rim
If you mount a new tyre with another
dimension, it might be possible that the
clearance between the front of your shoe and the
wheel will be reduced. This may make your foot
colliding with the front wheel while riding at low
speed and throw you off your bike!
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 cycling
on a rough surface. Rolling resistance decreases
with increasing pressure, but so does comfort. A high
tyre pressure is therefore most suitable for riding on
tarred roads.
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 for tubular tyres with road 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. This type of valve is designed for highest pres-
sures, but you need getting used to its handling. 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
Race or Sclaverand valve
Tyre pressure range
psi bar kPa psi bar kPa
80 5.5 550 130 9.0 900
90 6.2 620 140 9.7 970
100 6.9 690 150 10.3 1,034
110 7.6 760 160 11.0 1,103
120 8.3 830
Air pressure in psi, bar and kPa
Never inflate the tyre beyond its maximi-
mum air pressure. Otherwise it might burst
or come off the rim during the ride. Risk of an ac-
cident!
With race valves you first have to undo the
i
small knurled nut a little and press it in
carefully until air starts to escape.
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