R65LS shim in front wheel

[Landlubber]

I have noticed that there are available various shim sizes (shims) for the front wheels on the LS.

Please explain exactly what they are adjusting, they are in micron sizes (.05mm) as if they are very important, yet i can only see that they vary the depth the wheel bearings set....so what?

Thanks in advance. John

[Ed Miller]

Probably the bearing preload shims?  Here's an article on the wheel bearings.  He gets around to ones like ours farther down the page:

http://w6rec.com/duane/bmw/wheel_bearing/index.htm

[Rob Valdez 79 R65]

Is there an Airhead Beemers Club chapter in Brisbane?

There might be some folks who could help you through this, unless you are confident you could do it.

Write Duane.  He sells sets of the shims.

[Landlubber]

Ed and Rob, thanks for the replies, but neither of you have actually described how to do anything. The article is specific to very old models that had bearing caps etc to preload the bearings, the LS simply has bearings pressed into the cast alloy wheels, there is no pre or post load of the bearings that I can see other than the axle tension nut, and so what, it does not load the bearings to any specified torque setting that would be relevant to the "wedding band" shims I am referring to....my specific problem is that I do not see why a different sized shim would alter anything at all, the axle nut tension can still be ste at whatever...or am I totally lost?

[Bob_Roller]

According to the RealOEM BMW parts site, no shims are used on the LS style rims, with sealed bearings .

The shims are used on the older greasable type wheel bearings installed in the 'snowflake' type rims .

[Landlubber]

Yes, so sorry Rob, I actually am doing th rear wheel, I did write front wheel, but it is the rear wheel. Ta.

[nhmaf]

Da!

The front wheel bearings on the LS are of the sealed type and there is no specific preload requirement.   The REAR wheel bearings are of the older, grease-yourself type and are supposed to be set to a certain amount of preload, based on the the axle nut being set to spec with the proper shims.  However, BMW did also release a slightly different size tophat spacer that can be used to ever so slightly nudge the rear wheel a bit farther out from the cardan drive side.  This allows one to better fit a 120 series profile tire, though I think that they were originally intended for other purposes.  When the first snowflake wheels came out in 77{edit}, they didn't have steel insert reinforcements in the hubs, and so the bearings could wear "into" the alloy wheel, and thus require a different spacer for proper preload. Sometime in the 78-79 model year, BMW had steel inserts placed in the hubs of the wheels and this problem was solved as long as one had 1978+ year snowflakes.   The issue of bearing preload in the rear wheels and various wheel hub depths has always been a bit of a 'hot potato' with BMW.

[Rob Valdez 79 R65]

Yes - I forgot that the LS wheels are unique in their bearing arrangement.  
I have no information.

[Landlubber]

Thanks fellas for your help, much appreciated.