Isaac Kaon - Checking the Tyres

14 15
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Check your tyres for external damage and wear:
•theoriginalprofileoftherubbershouldbe
visible over the entire surface of the tyre.
•thepliesundertherubbermustnotbevisible.
•therubbermustnotexhibitanybulgesor
cracks.
Check the air pressure:
Check what type of tyres are fitted on your bike
Mountain bikes may be fitted with racing tires;
road bikes may be fitted with trekking tyres.
Rule of thumb:
Mountain bike tyre:
Tyre wider than 40 mm
Trekking/cross and fitness bike tyres:
Tyres are 28mm - 40mm wide
Road bike tyre:
Tyre narrower than 30mm
Check with your dealer what type of tyre is
fitted on your bike.
Guidelines for tyre pressure:
mountain bike tyres: 2.5 - 3.5 bar
trekking tyres: 3.5 - 5.0 bar
road bike tyres: 6.0 - 10.0 bar
Risk of personal injury and material damage!
If the tyre pressure is too low, there is a greater
risk of punctures and it becomes dangerous to
ride the bike. When going round a corner, the
tyre may come loose from the rim and start
to shift.
This can lead to dangerous riding situations,
crashes, accidents and damage to the bike.
Pump up the tyres to the specified pressure.
Air pressure is sometimes measured in the unit
‘psi’. You can use the table below to convert the
unit used.
The actual permissible air pressure can be
found in the information supplied by the tyre
and rim manufacturer.
The permissible tyre pressure is usually
indicated on the side of the tyre. Contact your
dealer for more information about this.
The heavier the cyclist, the greater the tyre
pressure needs to be.
7.1.3
3 Check your rims for dirt, especially oil and
grease.
4 Contaminated rims must be cleaned
immediately (see Section 12).
Checking the tyres
Check the position of the valve:
Risk of personal injury and material damage!
If the valve is slanted, the base of the valve
may break when riding the bike. This can cause
the tyre to deflate suddenly. This can lead to
dangerous riding situations, crashes, accidents
and damage to the bike.
Have a qualified bicycle mechanic fit the tyres
properly.
You can carry out these actions yourself if you
know how to remove and mount the wheels (see
Section 11.1) and replace tyres and inner tubes.
- If necessary, remove the valve nut.
- Check the position of the valve: valves should
point towards the centre of the wheel.
1 Check the rims for wear:
- Rims with wear indicators:
visual inspection
- Rims without wear indicators:
 •visualinspection
 •fingernailtest:runyourfingernailacross
the surface of the rim.
You shouldn’t be able to feel any grooves.
- If the wear indicator is no longer visible, or
if the rim has visible grooves or you can feel
grooves when doing the fingernail test, it
needs replacing.
2 Check the roundness of the rims:
 •Liftthebikeandspinthefrontwheeland
then the rear wheel.
 •Notethedistancebetweentherimand
brake pads. The maximum permissible
deviation per revolution is 2 mm.
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Rim with a groove as wear indicator.
Rim with dot as wear indicator.
Rim without wear indicator.
Correct valve position:
Valve points towards the centre of the wheel.
Incorrect valve position:
Valve does not point towards the centre of the
wheel.
psi
bar
30
2,1
40
2,8
50
3,5
60
4,1
70
4,8
80
5,5
90
6,2
100
6,9
110
7,6
120
8,3
130
9,0
140
9,7
Types of valves.
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Check the air pressure using a tyre pressure
gauge. Read the supplied manual or ask your
dealer for a demonstration before using the
tyre pressure gauge.
If the tyre pressure is too low: pump up the tyre
further.
If the tyre pressure is too high: open the valve
to let air escape and then check the tyre
pressure again.
If your bike pump has a pressure gauge, you can
check the pressure while pumping up the tyre.
Let some air out of the tyre first and then pump
up until the required tyre pressure is reached.
There are different types of valves available.
If the tyre has a ‘car’ or Dunlop valve, you can
attach the pump head directly onto the valve.
If the tyre has a ‚French‘ valve, you first need to
open the locking nut as far as possible before
attaching the pump and then close it fully once
you have finished pumping up the tyre. Ask
your dealer to show you how to do this.
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