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EBC brake shoes R75/5

eurotourer

New member
I recently installed a set of aftermarket front brake shoes (EBC) on my R75/5.
The result - hardly any brakes.
After taking the front wheel out I noticed that only an area of one inch long
and 1/8 inch wide on the inner side of both brake shoes were touching the drum
and that in the center part of the shoe.
I sanded the area down and got some brake action but still unsafe to ride.
Could it be that the mounting holes in the shoes are not 100% parallel to the lining
or am I just impatient of braking them in?
Meanwhile I cleaned up the original BMW shoes an reinstalled them so I can ride the bike.
Does anyone have a similar experience?
Thanks for a response
 
An old post on the forum talked about "arcing" the shoes to the drum. It's clear that the curve of the shoes need to match that that of the drum. But what I've read is that arcing shoes like that are now illegal in most states. But seems like it still needs to be done. I was able to do that on some shoes for my small R25/2 but I didn't have much to take care of. I put some sandpaper (maybe it was garnet paper or crocus cloth) on a sanding block and sand around the curve. I'd then reinstall the shoes, spin the wheel, and use light pressure on the brake lever to stop the wheel. Then I took the shoes out and see where the drum was hitting...finally kept attacking the areas that were not touching.
 
Kurt: Was it made illegal because of the taper not being cut back into the shoe, causing it to lock up?
 
franko -

I don't think I ever saw why. My WAG is that the fact that someone "messed" with brake shoes prior to use might have been done in a way that could have caused an accident. Just read someone on a Chevy forum where a possibility was that when brakes were made with asbestos, there was the possibility that the mechanic might inhale the dust. If that's the reason, I don't think that's the issue today. So maybe it's an issue that has gone by the wayside. I'd certainly work on the shoe surface to get them to fit the drums better. Supposedly the "wear in", but with reduced efficiency until that time, it's taking a risk.
 
Reposition the brakes shoes... e.g. take the "top" shoe and put it on the bottom, etc.

Years ago I pulled my front shoes and inadvertently switched them. The drum surfaces, after years of use, aren't really parallel; they develop a slight taper. The wear pattern was exactly as you describe it; although with only an 1/8" wide would seem to indicate that your drum is heavily worn.

It's a LONG shot, but easy to try.

Old Russian bikes (Urals and Dneprs) have notoriously bad drum brakes. The "fix" is often to use adhesive-backed sandpaper and stick it to the inside diameter of the brake drum. Install the wheel, and then lightly ride the brake (at low speed) to match the drum to the shoes. Crude... but effective.
 
you might be right about the drum worn out since the bike has over 80K miles on it.
I will measure the lining thickness of the old shoes on both edges. If they are equal
it must be a problem with the new shoes.
In that case I will enlarge the mounting hole just a touch so the shoe has some
side play and hopefully self adjust when braking.
 
If the inside radius of the drum is larger than the radius of the shoe material only a portion of the shoe can contact the drum. Pure geometry. When cars had drum brakes it was routine to grind the shoe radius to match the drum radius. Matching the two radius dimensions is the only way to obtain full contact.
 
I replaced my new ebc shoes with used stock bmw shoes off ebay. Stopped good and when I pulled to check shoes, it looked like they were making full contact. It is expensive to ship your wheel and backing plate off and have shoes arced.
 
I replaced my new ebc shoes with used stock bmw shoes off ebay. Stopped good and when I pulled to check shoes, it looked like they were making full contact. It is expensive to ship your wheel and backing plate off and have shoes arced.

Drum brakes have essentially become obsolete.
 
stupid me fighting with drum brakes that are obsolete.
Maybe it's time to buy a new bike with advanced technology.
Wonder what disc brakes are all about.

That, of course, was not my point. When I was a gearhead kid, getting new brake shoes arced was routine in any shop that specialized in brake work. Most of the corner gas station repair shops knew who to send the drums to in order to have the shoes fit correctly.

So now I read here that properly arcing brake shoes is "illegal". And apparently nobody knows how to do it for a motorcycle anymore. Back when I put new brake linings on a /5 in the early '80s the shop in Kansas City that relined the shoes had me measure the wheels so they could arc the linings to fit. A lost art it seems.

So "fighting it" is not the problem. The disappearance of the knowledge, skill and equipment to properly maintain and refurbish drum brakes is the problem.

I am positive that somewhere among the many shops that do maintain and restore old bikes there are folks who know how, and do properly refurbish drum brakes but so far in this thread the best I have read is that new shoes failed to work and putting old shoes back on worked better. That does not really sound like the real solution to me.
 
"bike has over 80K miles on it"

80 K is not many miles at all for life of typ drum unless unusual race use or heavy sand roads use

"drum brakes obsolete"

Drum brakes are best for collectors and bikes kept in storage for long periods - keep forever without damage
compared to hydraulic brakes which gum up and get very expensive to reclaim - I try to avoid hydraulic disk brakes
in my collection of riders - the R75/5 will be functional 50 years from now while BMW disk brakes will be toast and
parts unobtainum

I never tried it but the sandpaper stuck inside the drum idea but looks good to me - far better than arcing and deglazeing brake shoes
in my dad's auto dealership in the 1950s - the asbestos dust was distributed throughout the building by the big modine heaters and fans

Dad died from lung cancer from a lifetime of that and WWII exposure and smoking probably combined
 
That, of course, was not my point. When I was a gearhead kid, getting new brake shoes arced was routine in any shop that specialized in brake work. Most of the corner gas station repair shops knew who to send the drums to in order to have the shoes fit correctly.

So now I read here that properly arcing brake shoes is "illegal". And apparently nobody knows how to do it for a motorcycle anymore. Back when I put new brake linings on a /5 in the early '80s the shop in Kansas City that relined the shoes had me measure the wheels so they could arc the linings to fit. A lost art it seems.

So "fighting it" is not the problem. The disappearance of the knowledge, skill and equipment to properly maintain and refurbish drum brakes is the problem.

I am positive that somewhere among the many shops that do maintain and restore old bikes there are folks who know how, and do properly refurbish drum brakes but so far in this thread the best I have read is that new shoes failed to work and putting old shoes back on worked better. That does not really sound like the real solution to me.


We had our Husqvarna race bike shoes relined regularly. In a pinch we'd cut a strip of beer can material and wrap it around the brake cam to spread the shoes to meet the drum. Wet, muddy rear brakes never worked really well anyway.
 
I can't believe that ebc can't manufacture a shoe with a profile that more carefully matches the shoes they replace. Race tech in SoCal will arc your shoes for a couple hundred bucks. I don't believe new ebc shoes would ever bed in and work well without being arced. I'm pretty sure modern brake shoe material would work better but I'm not ready to spend the money yet. I think the stock brake works pretty good, as good as early disk brakes plus I think they look good.
 
I agree that it is not the final solution to put the old shoes back and I am not done until the EBC's fit properly.
It just have to take more time in my next attempt.
The idea with adhesive sand paper inside the drum sounds good. Did not think of it, Thanks.
 
The idea with adhesive sand paper inside the drum sounds good.

1 - make sure you have a GOOD respirator... not one of the cheesy paper one.

2 - adhesive-backed sanding strips can be found at an autobody supply store; start with 36 grit (no point in sanding for hours), finish with 100 grit. Cut to lengths so that the entire inside diameter of the drum is covered, but leave about 1/4" gap between stips to allow for dust build up.

3 - pick up a box of white chalk and use it to put lines across the width of the brake shoes. The sanding will reveal your progress. Re-apply chalk as needed.

4 - keep the sandpaper cleaned out with compressed air (if you have it). Replace the sandpaper as needed (sharp paper cut better) ... material is cheap, labor (your time) is not.

Read > Arcing Brake Shoes - SovietSteeds
 
I really appreciate your detailed info how to do it and what grit to use.
Eastwood sells rolls of this sandpaper and it may even be narrow enough so I only have to cut it to length.

Thanks again
 
I finally had time to address my brakes again.
The idea with adhesive sanding strips worked out great, very time consuming though especially the front brakes.
Lost count how many times I removed the wheels to check. A lot of material had to come off.
I should have bought BMW shoes.
 
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