rear drum brake

[garry a]

I have a 1989 100 GS with drum rear brake only just got it out on road the rear drum seams very week can't lock the rear wheel at all is this normal .front brake is fairly poor as well it's got an Honda xr600 complete front end on it small single disc but I think I can improve front with a clean up I don't think the caliper is sliding free. I've seen airheads with 1100 swing arm and disc on them how involved is this and any ideas what front end would be better I was thinking maybe Africa twin as twin disc.thanks for any replys or help

 

[ianboydsnr]

I have a 1989 100 GS with drum rear brake only just got it out on road the rear drum seams very week can't lock the rear wheel at all is this normal .front brake is fairly poor as well it's got an Honda xr600 complete front end on it small single disc but I think I can improve front with a clean up I don't think the caliper is sliding free. I've seen airheads with 1100 swing arm and disc on them how involved is this and any ideas what front end would be better I was thinking maybe Africa twin as twin disc.thanks for any replys or help

I think what to do is to get the brake shoes out and reline them, there are companies that do that, BMW shoe material is made out of unwearable substance, but the drums are not, they need a softer lining to work without wearing out the drum,

someone will be along with the name of a company that relines the shoes,

the front needs a bigger disc and better caliper, both available at a price!

 

[cheb]

XR650R front end? Fit a 320mm supermoto disc,I did and it works well. If you are really keen you can kep the cross spoke front wheel too though this does need some adaptors machining.

 

[garry a]

That sounds good I'll have a look around to see what I can find in my price range I have not got the original wheel which is a shame as they are not cheap either

 

[Voyager]

I recently had a pair of drum brake shoes relined by:

Brake Re-Line Services,
Unit 2,
West Point Industrial Estate,
Penarth Road,
Cardiff,
CF11 8JQ.
Tel: (029) 2070 2900
Fax: (029) 2071 1840

Mine were done with "3916 Asbestos-Free Material". Cost was £31.80.

I turned the complete backplate in the lathe to true-up the shoes and they work well.

This wasn't for a BMW - it was a TLS brake on a 'Classic' Ariel 500 - but it might be worth giving them a call. They don't appear to have a website or an e-mail address.

Bob.

 

[garry a]

Thanks for info I'll will give them a call

I recently had a pair of drum brake shoes relined by:

Brake Re-Line Services,
Unit 2,
West Point Industrial Estate,
Penarth Road,
Cardiff,
CF11 8JQ.
Tel: (029) 2070 2900
Fax: (029) 2071 1840

Mine were done with "3916 Asbestos-Free Material". Cost was £31.80.

I turned the complete backplate in the lathe to true-up the shoes and they work well.

This wasn't for a BMW - it was a TLS brake on a 'Classic' Ariel 500 - but it might be worth giving them a call. They don't appear to have a website or an e-mail address.

Bob.

 

[Beemerboff]

I recently bought a set of Lucas brake shoes on Ebay for my G/S quite cheaply, and now that they have bedded in they work better than stock.
It would be a problem chucking the final drive to skim them on a lathe, especially if it is still on the bike.

The brake pedal on the GS is part of the problem , it is too short and at the rear the bell crank is at an angle of around 135 degrees so you dont get much leverage. Some guys have cut it off and re welded it at 90 degrees, and report an improvement.

I have extended the front of my GS pedal with a L shaped piece of checker plate which gets my size 12s out from under the float bowl and gives me a bit more leverage, sowith a good prod I can just about tell it is working.

Before I spent too much money on the front I would fit some decent HH pads after cleaning the disk with a SS scouring pad. Low priced eBAY Armstrong HH sintered pads have proved to be as good as any, probably better than most. The Honda sliding calipers should work OK, they would stand my VFR on its nose with mt (slim and petite) missus on the back, but they must be sliding free or you only have one pad with half the leverage, so about one quarter power.

Your master cylinder may also be the wrong size for the Honda caliper, as it was sized to suit the large 48mm Brembo . Some Moto Guzzi's had a 11 mm master cylinder and if you can find one, or have your existing one sleeved down that would give a decent improvement too.
If your existing MC is 13mm you will notice the difference a 12mm makes, and they are a stock BMW item. But not cheap. Larger

 

[garry a]

Ok quick update on the brakes I'm going to try new shoes on the rear but I did find the cam was wrong way round according to Haynes not sure if it will make much difference . The front does have the Honda master cylinder but I have found that the calliper was seized and not sliding at all but the disc is warped and the wheel is buckled too not good. I have straightened the disc which is now much better but not perfect. But I have a new plan to fit front end from a 610 husky which I've just got off eBay it is complete wheel,forks,disc ,yokes,calliper ,master,cylinder even handlebars, and it's still on the frame so I have the headstock too. All for £40 quid