clicking sound when brakes are applied

[brant914]

Hi everyone...
this time I'm trying to help my brother in law.

He lives in stutgart, and is riding a 1993 R80R
he emailed me and asked about the brakes... because he thinks it is during braking at slow speed he gets a clicking sound

my first thought was to check the headset
so i told him to apply the brakes and while stopped... push forward and back on the front suspension
he claims no clicking in the headset.

I struggle to play mechanic from such a distance.
I'm also completely unfamiliar with the BMW front disk brakes

do any of you extremely knowledgeable experts know of a front brake, or common things that he should check on this model?
it might be a Euro model... I'm not sure.

brant

 

[20774]

I'm guess he thinks it's coming from the front brakes. Can he duplicate with the bike on the center stand and he spins the front tire? Try that and listen closely when applying the brakes.

 

[brant914]

Ok... I had him take a video on his phone.

its a dual rotor system (front)

in the video.. when he grabs the rotor on one side it moves 1/4 of an inch in and out
the other rotor does not move in his hand.
I think he found it.
I'm guessing the rotor mounting hardware is loose...
and when he 1st brakes the rotor clicks back into place.. .or back to square.. or something
I told him to replace the nuts (1 time use in chiltons) to proper torque

hopefully that is it
thanks and sorry to bug everyone

so much knowledge here


brant

 

[bubblehead617]

Hopefully the new bolts on the rotor fixes the problem! A rotor coming loose is scary!! I was the Chief Technical Inspector for WMRRA here in Washington. I've found two loose rotors on road-race bikes during Tech we had one bike loose the retaining pins on the front pads going down the front straight at 160+. Needless to say the bike didn't fare to well in the first turn. The rider managed to get it down to 80-90 with the rear brake before he biailed... he managed to walk away for the crash.During our 6 hour endurance races our pit crew checked rotors, etc at every rider change/refuel stop.

 

[stevenrankin]

Odds

Yeah, odds are pretty good he has found the problem. Rotors and stuff aren't supposed to wiggle side to side. Now the question is, upon disassembly to fix the problems has any damage been done to the rotors or wheel? I would make darn sure of no damage before I just replaced the bolts.

Just out of curiosity are these the stock rotors, is this still from the factory, or did someone have things apart to do repairs or restoration? If so, the owner may find himself infected with previous owner's disease. At that point, any work done by the previous owner becomes suspect and should be investigated.

I worked on a bike where the previous owner substituted cheap carriage bolts for fork brace bolts in order to install turn signals on the fork legs. I shudder to think what would have happened to the new owner if one or more of them broke during a ride.

Good luck and I hope this is just a one off thing. St