I've got a front brake issue- - -

[lsouth3]

On my 1980 R100RT. When braking the front of the bike "chatters". It's really more like a shudder. Pretty violent. It stops, but something's wrong.
I have removed the wheel and examined the calipers and pads.
All I find wrong is that one pad retainer spring (clip) is missing. It is on the left side and I really thought the chatter was in the right side. Would that missing spring cause the problem? It simply holds the non-driven
pad in place during assembly. (I thought) The pads appear to be about one half gone. Any Ideas?
Thanks
Lee

[Boxerkuh]

I don't know what you mean by shudder or chatter. You are saying the bike is braking, but is it soft, hard/harsh? Is the fuild up to par? Does the bike dive down under hard braking, so could it be a suspension problem or steering bearing issue? I am not sure I am understanding exactly what the problem is....

[benway]

do you feel pulsing in the brake lever?

it sounds like it could be a warped or uneven rotor

if its warped, I think you'll have to replace it.

rotate the wheel and look at the rotor head on. if its shuddering that violently, you will probably be able to see the runout/warp.

if its uneven, ie there is a surface deposit somewhere, I have read you can scour the surface of the rotor to remove it with some success. again you might be able to see it if the shudder is that pronounced

it could also be a loose wheel/bearings gone, but I'd start with the rotors.

hope that helps

[lsouth3]

Thanks for looking at the post. I should have stated that the bearings and suspension are good. No radical dive on braking. There is some flutter in the lever but not a lot. It may be feedback from the fork. I will check the rotors with a dial indicator but I am pretty sure they are both true. The sensation is a fast chatter which does not slow as the bike slows. It goes away at about 10mph. It is as if something is loose. These calipers are held in Place by one bearing bolt which is snug and not loose or sloppy. This design enables the calipers to pivot.
At this point I will replace the pads and clips as well as the o-rings on the bearing bolts. If the rotors are not true I will have to replace them, but I really think it's not the rotors. The bike has less that 35 thousand miles and has never had heating issues with the brakes.
Lee

[lsouth3]

Thanks again Boxerkuh and benway. I just came into Dallas this afternoon to get parts and one of the"oldtimers" in the shop (who is about 20 yrs younger than me) told me that the missing clip is the problem. It not only holds the pad in place during assembly it retains it solidly against the caliper frame during braking as well. Without it, the pad jitters in and out of position causing the problem. Mine is an older 80 model before brembo brakes.
Thanks again for your kindness.
Lee

[Boxerkuh]

I am glad that you found out what caused it. Thanks a lot for letting us know what it is for future reference.