BMW team handlebar horn ISDT 1979

[mingo]

Hello everyone I would like to know how the horns on the handlebar of the BMW ISDT Team from 1979 worked, were they electric or pump? Are they on the market or even something similar to them? Thank you

 

[ISDT79]

It is a very small horn with a rubber bubble (in black, red, blue...) to press with the fingers, all mechanic, no electrics.

I have never seen a similar horn (in german: Ballhupe) in the www, so if YOU find one, please let me know

Gruß

Werner

 

[mingo]

This horn is the more similar to the original that I have found in internet.
It needs some modification to looks like the original.
Thanks Werner!