The Rubber Cow

Gummikuh, Q, Kuh

German BMW fans call the two cylinder boxer engine R model motorcycles built between 1955-1990 Gummikuh or literally translated, Rubber Cow.

The term was created by the motorcycle journalist Ernst Leverkus (1922-1998), nicknamed Klacks, after a test ride of a BMW during which he noticed that when excelerating the bike’s back moved upwards and when releasing the accelerator moved downwards. This effect is caused by forces created by the cardan drive and the very softe suspension of the BMWs. Klacks compared this effect with the behaviour of cows when they get up with there back legs first. The effect is also called Fahrstuhleffekt or elevator effect.

(Some American web sites claim other sources of the term such as supposedly weak frame that wobbles when riding through curves. They obviously don`t have a clue.)

Gummikuh has been shortened and often BMWs are referred to as Kuh (cow) or just Q, which is pronounced the same way.

My own Rubber Cow, a 1972 BMW R75/5, in front of rice fields at the International Rice Research Institute (IRRI)