Front brake lever/switch quandary

[Altritter]

On Sunday I deadlined my bike after discovering in TCLOCKS that I "had no brake light."

Today has been my first chance to check it out. I went to a friend's auto repair shop (he has two beemers (one an R90/6—I think; can't keep the numeric suffixes straight)) and borrowed 2 bulbs, then back home to play and growl. Pulled the lens & discovered both bulbs burning.  :-?

Uh-oh, sez I: it's not a bulb. (DUH!) Played with it further & noticed that when I squeezed the front handle, nothing happened. But when I stepped on the rear brake, the brake light burned ever so slightly brighter. Slowly it dawns on me that the problem appears to be the front brake switch being on . Checked my Clymer's and bummed out—a lot of disassembly involved to reach the front switch, combined with what appears to be some painstaking reassembly.

During my self-pity session, I happened to brush the brake lever in the direction of the released position. The brake light went out!!!??? Played with it some more and discovered that although there is minimal brake lever free play, the brake switch is a hair trigger that activates at the slightest touch from the lever. Hurrah, it's not the switch!

But that raises another problem: Consulting Figure 8 on p. 15 of the R65 Rider's Handbook, I found the following text—"Checking free travel at handbrake lever [line skip here] Free travel at the handbrake lever is a fixed design feature, and cannot be reset." Ouch!

It occurs to me that there might have been a low-tension spring that kept the brake lever from contacting the switch, and that this spring might have been broken or lost sometime in the past 29.75 years. I haven't found an exploded view of the right handgrip/brake assemblies, so I don't know. Does anyone?

Otherwise, what are my options? I'd like to ride with two fingers lightly crooked over the brake lever, as numerous safety experts recommend. But I can't do that if I would be showing a constant brake light.

Any ideas? TIA,

JT

[Justin B.]

There is no adjustment for lever free-play but maybe you could unscrew the switch and shim it out with a thin washer to require a better squeeze to make it "engage".

[Bengt_Phorqs]

This may not apply to your situation but here's what I experienced.  You didn't say what year your bike is but mine is an 83 and I was having trouble with actuating the brake light with the front brake.  If you look very closely at the front brake perch you should see a wire with two female spade connectors.  One or both of these may be disconnected or corroded.  Try cleaning them and re-attaching to the male spade connectors.  I ended up having to put a cable tie wrap on the wire to hold it in place and keep if from coming off.

FYI, if you aren't familiar with the Max BMW microfiche you may want to check it out.  I bookmarked it and use it all the time.  
http://www.maxbmwmotorcycles.com/fiche/MainDiagrams.asp?mospid=47851

[Bob_Roller]

There's a good chance the switch is on the way to failure mode .

By all means check the wiring at the switch terminals .

You can remove the switch, it's just threaded into the hand grip casting .

You can try soaking the switch in alcohol, and then activate it numerous times in the alcohol, it may help to clean it out, but I'm on my third replacement switch on my '81 .

[Altritter]

Thanks for all the help. JT