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The pedelec has either:
•
a conventional valve
•
a Presta valve or
•
a Schrader valve.
Dunlop valve
The Dunlop valve, also known as a conventional
valve, is the valve in most widespread use. The
valve insert can be replaced easily and air can be
let out very quickly.
Figure 16: Dunlop valve
Presta valve
The Presta valve, also known as the French valve
(FV) or Sclaverand valve, is the narrowest variant
of all valves. The Presta valve requires a smaller
hole in the rim, which is why it is especially
suitable for the narrow rims on racing bikes. It is
about 4 to 5 g lighter than a Dunlop or Schrader
valve.
Figure 17: Presta valve
MY22K0a - 52_1.0_30.11.2021
Schrader valve
The Schrader valve can be pumped at filling
stations. Older and easy bicycle pumps are
unsuitable for filling tyres via a Schrader valve.
Figure 18: Schrader valve
3.3.4.4 Spoke
A spoke is a rod that connects the hub to the rim.
The bent end of the spoke which is hooked into
the hub is called the spoke head. A thread
between 10 mm and 15 mm is attached to the
other end of the spoke.
3.3.4.5 Spoke nipples
Spoke nipples are screw elements with an internal
thread which fits onto the spoke thread. Fitted
spokes are tensioned by tightening the spoke
nipples. This straightens the wheel uniformly.
3.3.4.6 Hub
The hub is located in the centre of the wheel. The
hub is connected to the rim and tyre with the
spokes. An axle runs through the hub, connecting
the hub with the fork at the front and with the
frame at the rear.
The hub's main task is to transfer the pedelec's
force of weight to the tyres. Special hubs on the
rear wheel perform additional functions. There is
a distinction between five types of hub:
•
Hubs without additional features
•
Brake hub, see Back-pedal brake
•
Gear hub, also known as a hub gear
•
Generator hub, see Hub dynamo
•
Motor hub.
Description
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