The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: bakio98 on April 08, 2009, 05:27:46 PM
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Has anyone heard of a retro change over to get rid of the rear drum to a disc brake? The lack of braking power sort of scares me.
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Don't forget braking is probably 75% front 25%rear, so if you boost the rear end you won't improve things too much, probably just make it easier to lock up the rear.
When you apply the brakes all you weight transfers to the front and the rear wheel lifts slightly.
You're better off looking at adapting the front wheel to a twin disc system.
John
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Actually having a rear disk makes rear-wheel removal/replacement somewhat more difficult, and over the years some have complained about the relative fussiness of the rear disks on airheads - they are more powerful, but again one has a much greater tendency to lock up the rear unless carryin a passenger to help keep the rubber down.
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There are tricks to making the rear grab better. Scuff the drum, new shoes, file the cam to make perfect contact with the shoe [or visa verse]
Reline shoes with softer pads but the best is to go over the front disc and make sure everything is in top nic. You could spend many hours on the breaking system. Time well worth the while. I've been on single disc R65's that were superior to dual disc models, It's all in attention to details. I think there are no less than 3 different disc pad compounds and 2 different discs available off the shelf. as good as all this is I've never seen an R65 do a "stoppie" tho.
rich
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... and hopefully your braking system doesn't become a "breaking system"
;)
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I have also heard that the rear disc set-up is less that ideal.
I have even heard of people converting back to a drum setup.
I would make sure your drum set-up is work properly first - check the angle of the connecting rod to the actuating arm - it can make all the difference.
Cheers
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My fiance had problems making quick stops - adding the second front disk was the cure. We used the original 12mm master cylinder and changed to SS brake lines. Much easier than adding a rear disk.
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Everything I have read indicates the drum (when working properly) is all you need. If you can lock up the rear tire then you can't get it to "grab" any more! A lot of people complain about the rear disc brake claiming that it does not brake as well as the drum but I can lock up the rear wheel on all of mine, disc or drum.
I suppose it would be possible to fit the rear disc components from an early R100RT or R100RS but I've not done it. You would need the rear wheel, caliper bracket, rear axle, caliper, lines, rear master cylinder w/linkages, brake fluid reservoir, etc.