The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Soeren on September 18, 2018, 05:20:02 AM
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I got new tires on my '83 R65, but the guy that installed them maneged to put the front tire on backwards. My question is, can I move the brake disk to the other side and flip the wheel? Will the disk and caliper align?
It would save me some time, to not have to take it back.
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I don't see any problem doing that. My '86 front wheel is symmetrical.
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Why not get the installer to correct his mistake?
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I don't see any problem doing that. My '86 front wheel is symmetrical.
I think they are not.
The wheel is "perfectly" centered in the fork legs by the axle and spacers. But the fabrication of the two bowls holding the brakes rotor is not that precise and if you wish that the rotor be centered into the not perfect caliper, you have to shim either the rotor bowl or the caliper. BMW choose to shim the rotor.
This goes for the left rotor.
On the right BMW has chosen to shim the caliper to take into account various tolerances on the fork legs and wheel thickness in manufacture...
So I would have the tire mounted correctly because finding the correct disks spot and shims to use is time consuming and tiresome...
Of course this is just my 2 cents...
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I think it will be quite OK as the dimensional difference allowed for by the shimming for the RHS caliper are very small.
I'd measure the clearance on the caliper as it is now, then remove the wheel, flip the disc and refit, then I'd measure and if the differences were small I would ride off happy.
I have fitted dual caliper systems to 3 R65s now, firstly to my wife's bike, thne mro erecently to bikes owned by others. I have never actually held one of the RHS caliper shims and frankly I only know of them through this group. None of the R65s I converted to dual caliper have had the slightest problem.
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The shimming on the right caliper, is accomplished by flanged bushings that go into the bolt holes on the right fork tube .
There are various thickness flanged bushings available .
Item #5 in the following IPC picture, called a sleeve here .
https://www.realoem.com/bmw/enUS/showparts?id=0364-USA-09-1980-248-BMW-R65&diagId=34_0598
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The shimming on the right caliper, is accomplished by flanged bushings that go into the bolt holes on the right fork tube .
There are various thickness flanged bushings available .
Item #5 in the following IPC picture, called a sleeve here .
In my view, based on the experience of fitting a second caliper to 3 bikes, a fairly typical piece of BMW overkill.
The K100 has no such "accessory", nor i think any of the later R series BMWs with twn Brembos.
Given the R65 was the first BMW with (potentially) twin "conventional" calipers I am inclined to think that someone in engineering thought it might be a problem and the shim/spacer/sleeve was produced as a solution to a non-problem.
As long as the caliper body does not contact the disc, hydraulics will ensure that both pads exert the same force on the disc and that they wear at about the same rate.
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I only have experience with an '86 Mono-shock and there were no shims/bushings when adding the 2nd disc/caliper. I think you could flip this wheel 180* with no problem but can't say on Soeren's '83.
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I flipped it and the disc was almost dead center in the caliper. ;)
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Great news!