The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: georgesgiralt on August 11, 2018, 08:06:36 AM
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Hello !
I've a rear wheel in desperate need of a new spindle. That's quite easy to solve. But this wheel has also a drum brake out of limit (and out of round). So I though I start to save to buy a new one from BMW. Alas they are NLA ...
Do you know a way to restore/exchange the drum ?
Thanks for your wisdom and advice !
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I guess one should use the front brake as much as they safely can
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I have had this done to an ancient japanese front wheel and see no reason why it wouldn't work for the BMW.
First, find a machine shop with a "gap bed" lathe and a faceplate (or a lathe big enough to swing the entire wheel [very unlikely]).
After mounting the wheel on the faceplate, turn the remains of the brake drum true (or alternatively If you know for sure that the brake band was "sweated" in after manufacture and not cast in when the hub / wheel was made - keep cutting it out until the brake band disintegrates, then clean up the hub.
Make a new brake band and machine the outer diameter so that it is a moderate interference fit to the hub/wheel.
Heat wheel / hub and chill brake band - press brake band into hub.
When cool, re-mount hub/wheel in lathe and turn the inside diameter of brake band until if is correct.
Now the problem with the above is that you need a BIG lathe, even for a gap-bed lathe to have an 18" swing. Then you need someone who knows how to drive it.
The above exercise, done at "mates rates" on an old Yamaha rim for me was still very expensive simply because of the amount of time it took.
I only undertook the project because I am half-heartedly restoring my old XT350 and of course front wheels for it have been NLA for decades and given the very brief life of the model any 2nd hand wheels have long been thrown away by the few wreckers still in business as unsaleable stock. Had I realized at the outset what a ghastly job it was I would have bought the entire disc brake front end from a later model and fitted it.
So, it is doable, it will cost lots. At least being the rear you can fit just about any drum brake BMW rear wheel.