1992 BMW K1100LT Front floating disc rotors

[Cliff]

Hi from Cliff NZ, Could any one enlighten me as to the amount of movement/play on the front K1100LT Disc rotors, before replacement of the "round things" that hold the disc's to the wheel hub. ( not sure of correct term )
but hopefully you will know what I mean. : :dunno2:

[rbm]

side to side about 1-1.5mm, rotationally zero mm. 

[johnny]

part number 20393 here at motobins...

j o

[Scott_]

I'd not be too sure of the motobins kit.
Not saying it's wrong, but the description seems to indicate that all 12 of the bobbins in the set are the same, when the bike actually requires 9 "standard  34 11 2 310 086   " and 3 "spring 34 11 2 310 995" type bobbins per rotor.

[Inge K.]

And.....since the Motobins kit have steel bobbins, I'll guess it would put more wear to the dischubs and discs
than the genuine ones in alu.

[johnny]

dang... caints believe i laid the whole deal out with part numbers and links and clicked remove...

i defer to the mayor of marshalltown and the mayor of fredrikstad cause i donts know ch1t...

so... doo your doo dilergence... the 92 may be different than the 96...

92 lt...

96 rs...

the fiche looks kinda fichey...

from 3-17-12... 96 k1100 rs...

i scored the stainless bobbins #20393 from motobins which were recieved in california 4 days after ordered from the uk at approx $65 per side...

burd bobbins at approx 80k miles...





removal of oem...







buttoned up...






j o

[drut]

Those stainless bobbins look good,notice on the motobins site they are are made by Grimeca.If the damage shown in Johnny's pics is common I don't think too much of the originals.

[jacksdad1963]

I've just replaced my discs with a pair off another bike, because they had no visible wear, but now my brakes shake like crazy  :yow
I've fitted the discs with a full set of identical bobbins/circlips whatever you call them: I did notice about 3 were different, but I've not used these, just fitted all the same.
I don't really see how different mounting bobbins/circlips will make any difference but I'm often wrong!
Any advice much needed! Thanks, Mike

[Scott_]

The 3 bobbins with the "spring ring" are supposed to help manage the "rotational float" of the disk on the carrier and keep the slack to a minimum.
The oem bobbins are aluminum, my understanding is that they are intended to be the "consumable wear" item connecting the disk rotors to the carriers.

I replaced all the bobbins on both my bikes last year, less expensive than trying to replace the disk rotor, and/or the carrier. Btw, I don't see the carriers listed anywhere as being available new.

[Cliff]

Hi from Cliff NZ, Thank you all very much for the info. looks like a set of s/s bobbins from Motobin should do the trick. Thanks Johnny those pic's say it all.
Cheers
Adventure before Dementure.

[Duc750]

The stainless ones don't seem to increase wear noticeably. Well my discs were gone before the bobbins lets put it that way and the carriers are still going. If you need new discs though it's worth looking at brembo  as they come ore assembled with new carriers for less than discs and bobbins

[drut]

I've just replaced my discs with a pair off another bike, because they had no visible wear, but now my brakes shake like crazy  :yow
I've fitted the discs with a full set of identical bobbins/circlips whatever you call them: I did notice about 3 were different, but I've not used these, just fitted all the same.
I don't really see how different mounting bobbins/circlips will make any difference but I'm often wrong!
Any advice much needed! Thanks, Mike

"10) Be prepared for some slight �pulsing� of the brake, giving the impression of a warped disc, until the new bobbins have seated correctly. This may take a few days of use."
Taken from another forum : http://forum.bmw-club.org.uk/viewtopic.php?t=7395