Bosch ZEMO SU-E FS 12 - Tyres; Adjust Tyre Pressure

MY22Z0a - 12_1.0_25.07.2022
127
Operation
6.5.10 Tyres
6.5.10.1 Adjust tyre pressure
The correct tyre pressure largely depends on the
weight load on the tyres. This load is determined
by the weight of the pedelec, the rider’s body
weight and the luggage load.
Unlike cars, the weight of the vehicle has little
impact on the total weight. Moreover, the personal
preferences for low rolling resistance or a high
degree of suspension comfort vary a great deal.
It is important to remember that
• the higher the tyre pressure is, the lower the wear,
rolling resistance and the risk of breakdown are.
• The lower the pressure in the tyre is, the greater
the comfort and grip that the tyre offers is.
In the case of pedelecs used on the road, the rule
is the greater the tyre pressure is, the lower the
tyre rolling resistance is. The risk of breakdown is
also lower when the pressure is high. A
permanently excessively low tyre pressure often
leads to premature wear in the tyre. Cracking in
the side wall is a typical consequence of very low
tyre pressure. Abrasion is also unnecessarily
high.
On the other hand, a tyre can absorb road impacts
more effectively at a low pressure.
As a general rule, wide tyres are operated at a
lower tyre pressure. They provide the option of
exploiting the advantages of the lower tyre
pressure without the serious disadvantages it
causes with regard to wear, rolling resistance and
breakdown protection.
 Never exceed or go below the minimum and
maximum pressure limits indicated on the tyre.
1 Pump the tyre to the recommend tyre pressure.
2 Perform a visual check on tyres.
Figure 139: Correct tyre pressure. The tyre is barely
deformed under the load of the body weight
Figure 140: Much too little tyre pressure
Tyre width
Tyre pressure in bar for body
weight
approx.
60 kg
approx.
80 kg
approx.
110 kg
25 mm 6.0 7.0 8.0
28 mm 5.5 6.5 7.5
32 mm 4.5 5.5 6.5
37 mm 4.0 5.0 6.0
40 mm 3.5 4.5 6.0
47 mm 3.0 4.0 5.0
50 mm 2.5 4.0 5.0
55 mm 2.0 3.0 4.0
60 mm 2.0 3.0 4.0
Table 39: SCHWALBE recommend tyre pressure