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BMW R80 1984 rear brake light switch - 61 31 1 459 747
- Thread starter carvalholmd4490680
- Start date
stevenrankin
Well-known member
One of the worst cases of "Previous Owner's Disease", I have ever seen. I have to admit when I first read you post I was flabbergasted as to how someone could not figure out a way to change the rear brake light switch.
Then you did a good thing and posted pictures. Question answered in one photo.
LOL, yeah, the factory switches are kind of in an awkward place and such but not too bad compared to other things. But to have someone saw off the mount and BS another mount makes no sense to me.
I hate seeing good bikes chopped up to make "custom" bikes, that is my opinion. Good luck with the fix. St.
Then you did a good thing and posted pictures. Question answered in one photo.
LOL, yeah, the factory switches are kind of in an awkward place and such but not too bad compared to other things. But to have someone saw off the mount and BS another mount makes no sense to me.
I hate seeing good bikes chopped up to make "custom" bikes, that is my opinion. Good luck with the fix. St.
olironrider
Active member
… while you’re figuring out a rear brake switch mount, how about posting a picture of your bike; view of the right side would be nice.
As you may know by now… we like pictures
As you may know by now… we like pictures
carvalholmd4490680
New member
… while you’re figuring out a rear brake switch mount, how about posting a picture of your bike; view of the right side would be nice.
As you may know by now… we like pictures
Attachments
olironrider
Active member
Nice Cafe’… very nice ! I knew more had been done to it 
While you’re thinking about the rear brake switch mounting; I dug through pictures of my restoring the 1973 R 60/5, particularly that area. Nearly all the Airheads I’ve restored had a common “factory induced failure” in both the left & right rear foot peg/silencer mounts !
Incidental to that work, the original rear brake switch mount is shown; the web (circled in RED) has always been cracked/broken and more often than not, has a gap which I close during repair…
Such a miserably small cross-section therein, cannot withstand the harmonic vibrations of the silencers ! The over-hung moment has to be huge ! I fabricate a doubler from chrome-molybdenum steel that reinforces that very small cross-section and, distributes the stresses further into the structure (cardboard pattern), checking for clearance with the rear brake pedal…
Weld them in, top & bottom (initial tacking-in shown) on both sides in the same areas. Often, I re-weld the less than optimal factory oxy/acet welds, as you can see by the bluing near the right down tube and brake switch mount, above…
That rear brake switch mount is two(2) pieces; the upward 90* bend has a thru-hole for the small diameter rod portion of the switch itself, that extends beyond the metal and contacts the brake pedal M6-1.0 adjuster/stop bolt.
Hopefully, you can see how much original material was removed on your Cafe’ as well as, giving you ideas for your “field fabricated” mount ?
While you’re thinking about the rear brake switch mounting; I dug through pictures of my restoring the 1973 R 60/5, particularly that area. Nearly all the Airheads I’ve restored had a common “factory induced failure” in both the left & right rear foot peg/silencer mounts !
Incidental to that work, the original rear brake switch mount is shown; the web (circled in RED) has always been cracked/broken and more often than not, has a gap which I close during repair…
Such a miserably small cross-section therein, cannot withstand the harmonic vibrations of the silencers ! The over-hung moment has to be huge ! I fabricate a doubler from chrome-molybdenum steel that reinforces that very small cross-section and, distributes the stresses further into the structure (cardboard pattern), checking for clearance with the rear brake pedal…
Weld them in, top & bottom (initial tacking-in shown) on both sides in the same areas. Often, I re-weld the less than optimal factory oxy/acet welds, as you can see by the bluing near the right down tube and brake switch mount, above…
That rear brake switch mount is two(2) pieces; the upward 90* bend has a thru-hole for the small diameter rod portion of the switch itself, that extends beyond the metal and contacts the brake pedal M6-1.0 adjuster/stop bolt.
Hopefully, you can see how much original material was removed on your Cafe’ as well as, giving you ideas for your “field fabricated” mount ?
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carvalholmd4490680
New member
This is so helpful. Thanks!!!Nice Cafe’… very nice ! I knew more had been done to it
While you’re thinking about the rear brake switch mounting; I dug through pictures of my restoring the 1973 R 60/5, particularly that area. Nearly all the Airheads I’ve restored had a common “factory induced failure” in both the left & right rear foot peg/silencer mounts !
Incidental to that work, the original rear brake switch mount is shown; the web (circled in RED) has always been cracked/broken and more often than not, has a gap which I close during repair…
View attachment 101385
View attachment 101386
Such a miserably small cross-section therein, cannot withstand the harmonic vibrations of the silencers ! The over-hung moment has to be huge ! I fabricate a doubler from chrome-molybdenum steel that reinforces that very small cross-section and, distributes the stresses further into the structure (cardboard pattern), checking for clearance with the rear brake pedal…
View attachment 101387
Weld them in, top & bottom (initial tacking-in shown). Often, I re-weld the less than optimal factory oxy/acet welds, as you can see the by the bluing near the right down tube and brake switch mount, above…
View attachment 101388
That rear brake switch mount is two(2) pieces; the upward 90* bend has a thru-hole for the small diameter rod portion of the switch itself, that extends beyond the metal and contacts the brake pedal M6-1.0 adjuster/stop bolt.
Hopefully, you can see how much original material was removed on your Cafe’ as well as, giving you ideas for your “field fabricated” mount ?
If its not a complicated, can i ask the dimensions of the support (horizontal and vertical) ?
I’ve working on my bike for some time, restored the stock controls, motor, eletrics, brakes, and as been worth and grateful to learn about everything. Still a long way to go. Prefered the bike as original, but for the price i bought its a good price still with the problems it as bring me
olironrider
Active member
… a few more pictures of the area around the rear brake switch mount (bike is 1976 R 90/6, 2/76 build). I noticed that BMW switched from a two(2) piece mount like on the /5s, to a one(1) piece stamping (more below about the RED circle)…
This bike had serious cracks on both left & right frame mounts for the silencers, rear pegs and, rear brake pedal ! As a matter of fact, the right frame mount was twisted/broken by the lever/arm, created from repeated use of the rear brake pedal…
Note the skewed relationship between the level engine thru-bolts, main frame cross members, and the rear brake pedal pivot ! Here’s a close-in view…
In this image with a rear brake pedal installed, the out-of-position situation is obvious…
It appears that someone re-formed your rear brake pedal at it’s connection to the rear brake rod, to compensate for a skewed brake pedal pivot point…
Here, the correct orientation of the rear brake switch mount is shown…
I’ll work on the details of the rear brake switch mount measurements however, I think you’re going to have to fabricate a “one-off”, based upon mounting it in place of your existing rear brake pedal stop ?
You might also check on the frame mount at the rear brake pedal pivot… for cracks ?
This bike had serious cracks on both left & right frame mounts for the silencers, rear pegs and, rear brake pedal ! As a matter of fact, the right frame mount was twisted/broken by the lever/arm, created from repeated use of the rear brake pedal…
Note the skewed relationship between the level engine thru-bolts, main frame cross members, and the rear brake pedal pivot ! Here’s a close-in view…
In this image with a rear brake pedal installed, the out-of-position situation is obvious…
It appears that someone re-formed your rear brake pedal at it’s connection to the rear brake rod, to compensate for a skewed brake pedal pivot point…
Here, the correct orientation of the rear brake switch mount is shown…
I’ll work on the details of the rear brake switch mount measurements however, I think you’re going to have to fabricate a “one-off”, based upon mounting it in place of your existing rear brake pedal stop ?
You might also check on the frame mount at the rear brake pedal pivot… for cracks ?
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olironrider
Active member
It appears from your license plate, you are in Portugal ?
I will dimension the rear brake switch mount in both inch and metric…
I will dimension the rear brake switch mount in both inch and metric…
stevenrankin
Well-known member
My friend had a "customized" airhead come into his shop for various handling and electrical issues. The guy who did the customization had decided he knew better than BMW what components worked "best". Six weeks later, the poor second owner of this mess rode out a happy camper with BMW switch gear and such a very happy camper. Unfortunately he also had a lighter wallet.
I guess this is a warning to those who look at these custom bikes to take a real long look at what they might be getting into before purchasing a "custom" bike. NOT ALL shops are competent to do such work even though they think they are. They get the big buck in their pockets for their creativity and someone get their wallet emptied trying to get a comfortable/reliable bike to ride.
My understanding of cafe racers is that they were built as a showcase for individual talent and desire to have something better and a one off bike. That is fine for some people and hey, I have seen some custom built bikes that look really cool and that I would be tempted to buy. But, I always shudder at the thought of trying to repair or maintain said bikes when they break down. BMW bikes are/were pretty near perfect stock and while far simpler to maintain and ride stock, some improvements can be made to them to achieve near perfection without so many radical changes. Not all BMW stock parts are junk to be improved upon. I guess I feel this way because I ride the heck out of my bikes and don't like working on them at all even stock but, it must be frustrating to try to replace a one off part that looks pretty yet is far from reliable or easy to fix.
Good luck in returning your pretty bike back to a reliable easy to work on steed. St.
I guess this is a warning to those who look at these custom bikes to take a real long look at what they might be getting into before purchasing a "custom" bike. NOT ALL shops are competent to do such work even though they think they are. They get the big buck in their pockets for their creativity and someone get their wallet emptied trying to get a comfortable/reliable bike to ride.
My understanding of cafe racers is that they were built as a showcase for individual talent and desire to have something better and a one off bike. That is fine for some people and hey, I have seen some custom built bikes that look really cool and that I would be tempted to buy. But, I always shudder at the thought of trying to repair or maintain said bikes when they break down. BMW bikes are/were pretty near perfect stock and while far simpler to maintain and ride stock, some improvements can be made to them to achieve near perfection without so many radical changes. Not all BMW stock parts are junk to be improved upon. I guess I feel this way because I ride the heck out of my bikes and don't like working on them at all even stock but, it must be frustrating to try to replace a one off part that looks pretty yet is far from reliable or easy to fix.
Good luck in returning your pretty bike back to a reliable easy to work on steed. St.
carvalholmd4490680
New member
Thank you. That will help
