Restoration of a 1990 R100gs

Hello

Sorry but I don't know of any uk retailer. You will have to look further afield - continental Europe or USA.

All available systems in the UK had either brushes or were potentially incompatible with dry cell batteries.
 
It will never be as clean again!

Some photos below of bike. This stage of her restoration is complete.

Possible further steps will be:

1. Bespoke cockpit

2. Further suspension upgrades - WP would be nice

3. Ignition upgrades

4. Gearbox with kickstart

But until then I hope to enjoy riding her at least as much as I did prior to all the upgrades but in the meantime the lock down continues here in Wales so no outings but plenty to look forward to.
 

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Remember kickstarting AFAIK require a different ICU. Just mentioning it in case you upgrade ignition before the gearbox.
 
R100GS Restoration - rear brake "upgrade"

R100gs Rear Brake Upgrade -

I along with many early GS owners have encountered rear brake problems.
I have undertaken many upgrades to my bike (as many others also have) and I felt it would be remiss of me to make improvements to my bike without addressing the issue of the rear brake.
I am aware of solutions previously adopted by others for example:
1. Changing the back end for a r1100gs set up (no doubt there are other reasons for this upgrade but the ability to fix a disc to the rear has to be one of the reasons for this change).
2. HPN rear disc upgrade - I seem to recall that HPN offered a mounting plate for a rear disc (aswell as HPN's upgrade to an inverted brake cam enabling continued use of the rear shoe system)
3. Welding tabs on to the brake cam so that the shoes would move further apart.

So what is the problem and are all R80/ 100 gs's affected?


Assuming the brake drum is within acceptable tolerances (mine was and I drew this conclusion because I could adjust the rear brake so that they stuck on), the main issue seems to be that the brake pedal does not have sufficient movement to actuate the brake cam without the brakes been adjusted so that they are continually rubbing. What system do I have? - I have the one with the oddly shaped brake cam and shoes.


I used to have a r65 and it had brake shoes and I found the back brakes worked very well - at least as well as the rear disc brake on my 1983 r100rt (probably the best bike ever made in my view).

The r65 had a flat edged brake cam and the shoes had a flat end. It semed to me that a better spread of the shoes would be available for a more limited pedal movement if I used this earlier form of brake cam with the appropriate shoes. Indeed I think this system was used on 1991 onwards GS models.

I bought a new flat brake cam on ebay and appropriate shoes and am pleased to report a significant improvement on stopping power. So if you want a cheap solution to rear brake problems you might like to try this out.


Any works you do is obviously at your own risk and I accept no responsibility (sorry!)

Photos attached showing new cam, new shoes and old type of shoe
 

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David Ty Cae said:
R100gs Rear Brake Upgrade -

I along with many early GS owners have encountered rear brake problems.
I have undertaken many upgrades to my bike (as many others also have) and I felt it would be remiss of me to make improvements to my bike without addressing the issue of the rear brake.
I am aware of solutions previously adopted by others for example:
1. Changing the back end for a r1100gs set up (no doubt there are other reasons for this upgrade but the ability to fix a disc to the rear has to be one of the reasons for this change).
2. HPN rear disc upgrade - I seem to recall that HPN offered a mounting plate for a rear disc (aswell as HPN's upgrade to an inverted brake cam enabling continued use of the rear shoe system)
3. Welding tabs on to the brake cam so that the shoes would move further apart.

So what is the problem and are all R80/ 100 gs's affected?


Assuming the brake drum is within acceptable tolerances (mine was and I drew this conclusion because I could adjust the rear brake so that they stuck on), the main issue seems to be that the brake pedal does not have sufficient movement to actuate the brake cam without the brakes been adjusted so that they are continually rubbing. What system do I have? - I have the one with the oddly shaped brake cam and shoes.


I used to have a r65 and it had brake shoes and I found the back brakes worked very well - at least as well as the rear disc brake on my 1983 r100rt (probably the best bike ever made in my view).

The r65 had a flat edged brake cam and the shoes had a flat end. It semed to me that a better spread of the shoes would be available for a more limited pedal movement if I used this earlier form of brake cam with the appropriate shoes. Indeed I think this system was used on 1991 onwards GS models.

I bought a new flat brake cam on ebay and appropriate shoes and am pleased to report a significant improvement on stopping power. So if you want a cheap solution to rear brake problems you might like to try this out.


Any works you do is obviously at your own risk and I accept no responsibility (sorry!)

Photos attached showing new cam, new shoes and old type of shoe
Click to expand...

So, to be clear, that's an R65 cam and shoes?
 
This is an interesting mod for that bike.

sheene said:
how much is it ??
Click to expand...

I took a look at Motorworks website and they list no less than 7 rear brake cams. The prices are there. Depending on what bike you have, and what year, will dictate what parts will fit, and hence the price.

Cost all the items, as there are the different brake shoes, cam washers, pivots, springs and rubber dampers too. Do you own research! They are your brakes!
 
David, I went to the trouble of fitting the HPN floating rear brake arm, and to be honest the rear brakes were still awful!
The bike was an 89 paralever. I had more success with the front I fitted dual discs & 4 pot calipers from the 16 valve models, similar to what the 'Mystic's' had. It was not up to modern standards, but ten times better than that awful wooden, single caliper that comes as standard.
A rear disc would be ideal, but I would imagine that entails a hell of a lot of work.
 
Hello All

I found the brake cam on ebay. The cam was sold by a private seller and had the following description "Leva freno trasero para/Rear brake cam for BMW R80-100GS/Basic/R/Mystic"

As mentioned this was a private seller I am not sure that this description is accurate but it could be - motobins sell the flat faced shoes (although I cannot see the corresponding flat cam actuator advertised. A bit of further investigation is thus required although you could try and buy an inexpensive flat cam actuator on e bay and then buy the appropriate shoes and see how it works out. If it all fails you will have lost £100 or so but if it works for you like it has for me then you will find your brakes significantly improved without spending much money or making any visible external modifications. If the worst happens and the rear brake fails to operate you are probably in the same position as you are already in! Incidentally I bought a range of springs but I needn't have bothered - the old springs would have worked just fine.

In terms of the front brake, I have a stainless steel 320mm Seibenrock disc with adaptor plate. I also have a steel braided pipe. This combination has improved the front braking quite a bit. I have retained the stock Brembo single pot caliper. I do however like the sound of Cheney's upgrade -in particular a dual disc set up.

I had considered the rear disc upgrade option. I have a HPN adaptor plate for a rear disc conversion but like everything else -one change inevitably involves making many more and the improvement in the rear brake is such that I don't see the need to do further work.

A few R100 GS owners have of course replaced from the gearbox back with an R1100gs back end. Others have just used the r1100gs bevel drive. There are of course specialist engineers both abroad and more importantly here in the UK who could help with fabrication, I am sure. RM would probably be a good port of call.

Usual disclaimer ie only an axe wielding monkey should undertake any of the works I have mentioned -it's on your own head
 
Any local Ferodo agent will be able to re-line your old shoes with modern material of the required thickness.

Many years ago I had a mono R100RS which had the black/silver alloy rims with sharp spoke edges..

The rear drum section was worn slightly oversize, but there was nowhere that would rebuild the wheel with a new drum insert.
With a light skim to remove the lip, and a pair of +3mm brake linings, full brake effort was restored.
 
Hello Chopper Harris

Names of companies which will reline the drum and offer the services to which you refer would probably be appreciated by many readers. Please post.


If anyone proceeds along the lines I have suggested, I would be interested to know if they have also had the same positive results which I have had so please let me know.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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