Schrader tyre valve caps

  

In the questionnaire ( page 5) on Military Motor Cycles, prepared by the Royal Artillery Mechanical Traction School, you can read that from 29-04-1941 the military used the clever Schrader Dublchek tyre valve caps on all motorcycles. Before that time they used the Schrader valve caps that were combined with a tool for removing tyre valve centres as can be seen in the picture below.
 

 

The early model Schrader valve cap combined with valve core removal tool as used on an original factory photo of a 1940 WM20 proto type.

 

From 29-04-1941 the military ordered the use of the clever Schrader Dublchek valve cap for all motorcycles. This Schrader Dublchek valve cap made it possible to inflate, deflate, or test pressure  without taking the valve cap from the valve. This way the valve cap couldn't get lost preventing dirt getting in the valve and tyre.

 

The clever Schrader Dublchek valve cap as used during the war on all motorcycles from 29-04-1941.
 

From the moment the Schrader Dublchek valve cap was put in use, a tool (66-9161) for removing Tyre Valve Centres was added to the toolkit.
 

 

Schrader Dublchek valve cap boxes. The cap that can't be lost.
 

schrader valve cap 05.jpg (591662 bytes)

This ad from a 1931 paper for the "New Schrader DUBLCHEK valve cap" clearly shows how this valve cap works. Click on the ad to enlarge it.