Clutch housing (mirror LH thread)

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Pierre Michaud

Clutch housing (mirror LH thread)

Post by Pierre Michaud »

Why is the thread on the handlebar clutch housing Left handed? Please do not answer "because the mirror stem is threaded that way"! I just purchased an insert (LH) to repair the bad threads on the housing I have. The original threads on my housing are right handed. Every document I have read says the threads are LH! Why are my threads RH then?
Mark Huggett

Re: Clutch housing (mirror LH thread)

Post by Mark Huggett »

Pierre,

A LH thread for the mirror mount on the clutch lever armature is not uncommon and is found on many machines, Japanese and continental alike. The old fashioned rear view mirror on a motorcycle offers a great deal of wind resistance. If the right hand side mirror had a RH thread in the clutch lever armature, the continous buffeting from the wind while riding would have the tendency to continuously loosen the mirror. I have made this experience on some or other bike with a RH thread on the RH rear view mirror, and the damned thing kept on loosening by its self. Damned frustrating!

Regards,

Mark
Mark Huggett GmbH
Pierre Michaud

Re: Clutch housing (mirror LH thread)

Post by Pierre Michaud »

Mark,
Thanks for explanation. It makes good sense. When did BMW stop turning out clutch castings with mirror RH thread then, as mine (1967) is RH threaded?
Mark Huggett

Re: Clutch housing (mirror LH thread)

Post by Mark Huggett »

Hi Pierre

I'm not sure when BMW stopped the LH thread in the clutch armature, but it must have been some time in the early seventies possibly with the /6 series. It was a continuous problem with the thread stripping in the zinc casting so Magura eventually just drilled a hole right through the housing were the lever is slotted into, and locked the mirror in place with a lock nut on the underside, and of course, a RH thread.

Regards,

Mark
Mark Huggett GmbH
Pierre Michaud

Re: Clutch housing (mirror LH thread)

Post by Pierre Michaud »

Mark,
I have a feeling from your description of the clutch casting that I do not have an original on my 1967 R69S. The clutch housing I have has a right hand thread and there is no recess underneath to fit a lock nut. Could it be a /5 or /6 casting? Also, the high and low switch has a knob similar to a horn button that you can push which I believe would actuate the flasher. This switch has two separate branches, one with 2 wires and the other with 3 wires. this does not agree with the wiring diagram I have. The part also looks newer than the switch on the front brake casting which lodges the turn signal/horn swivel switch. My instuction manual shows both switches to be identical to the turn swivel switch I have which looks the same age as the Motorcycle.
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