Operation Manual

Cycle Wheels and tyres
81
With the exception of tubular tyres and UST tyres, the tyre and rim alone are not airtight.
An inner tube is used to keep air inside the tyre, and this is filled via a valve.
10.1.1 Valve types
Cycles may be equipped with one of the following valve types (see “Illustr.: Valve types”):
– Presta valve (PV): secured with a tappet
in the valve, rim hole 6.5 mm/0.26",
maximum pressure 217.5 psi.
– Dunlop valve (DV): secured with a union
nut, rim hole 8.5 mm/0.33", maximum
pressure 87 psi.
– Schrader valve (SV): secured with a
tappet in the valve, rim hole
8.5 mm/0.33", maximum pressure
145 psi.
All three valve types have a valve cap to
prevent the valve getting dirty.
1
2
4
3
PV DV SV
Illustr.: Valve types (example)
1 Knurled screw
2 Valve tappet
3 Lower knurled nut
4 Upper knurled nut