The rear brake on my 2001 280 edition is constantly becoming loose at the main bolt that holds it on, which is getting really annoying as when loose the lever tucks itself under the clutch case and is hard to use

Ive tried loctite to no avail, and figured this might be pretty common and have some clever fix everyone but me knows about....

The bolt itself is threaded along its whole length, and i was wondering if this is normal, it seems like a bolt with an unthreaded section could be tightened up properly without binding the brake lever, which exactly what is happening to me at the moment when i try to get it tight.

 

Any thoughts, perhaps im missing something?

 I believe it had a special bolt and nut originally. Have you looked at the parts diagram?

If the bolt you have locks the brake lever in place when you tighten it, surely you need a longer one, ie one which tightens fully in the threads leaving an exposed length of bolt which is slightly greater than the thickness of the brake lever. In this way the lever will be free to operate and the bolt won't come loose as it will be fully tightened (a smear of Loctite would always help as well).

4 hours ago, lineaway said:

 I believe it had a special bolt and nut originally. Have you looked at the parts diagram?

the diagram isnt much help, it shows a bolt but not in any useful detail, and a websearch of the part no. doesn't bring up a picture either

i think perhaps whats happening is that there was/is a steel bush/sleeve inside the alu brake lever which the bolt tightens against, and the lever pivots on. I suspect my bush has either worn flush with the pedal or is seized together with it, hence the binding when the bolt is tightened. Does this sound right?

Also, im used to a return spring on a rear brake lever which mine doesn't have, so it doesn't take much to prevent the lever returning properly just from the hydraulic pressure from the master cylinder. Should i have one or is this a trials tactic to shave of precious grammes?

hopefully i will get a chance to have a proper look at it all tomorrow

 

This is what a modern GG looks like, specifically 8 and 9. There is no return spring, just a stop screw on the pedal.

The pedal itself, with the 'nut' (8) make up a bushing: the nut (8) slides into the opening on the pedal and is lubricated with a small amount of grease. You can tighten the screw as much as you want, the pedal will not bind (unless you manage to pull the nut through the frame, which would be quite something). It's slightly confusing from the parts diagram, but the bolt (9) first goes through the frame obviously.

 

 

Edited December 12, 20178 yr by heffergm

Apply loctite and tighten to still allow movement then leave it overnight. Sorted

drill the rim of the bolt + the bikes frame & use a lock wire.

6 hours ago, anotherfive said:

Apply loctite and tighten to still allow movement then leave it overnight. Sorted

i only used blue before, a little red might do the trick

 

3 hours ago, perce said:

drill the rim of the bolt + the bikes frame & use a lock wire.

not a bad idea, i will bear it in mind when i get under there for a proper look at it all

 

Thanks for your help guys, i haven't had a chance to spend any time in the workshop yet, but am ever hopeful

Have sorted this now, so thought i would report back in case it is of help to anyone else....

 

The pedal on my 2001 280 edition model is unlike that in the diagram above posted by heffergm, its held on by a bolt into a threaded hole in the frame. the bolt passes through an aluminum sleeve/spacer that is itself within a steel bush pressed into the aluminum lever. the sleeve needs to be longer than the bush and lever body or the whole thing will bind when the bolt is tightened.

 

i guess inevitably the spacer will eventually wear flush with the steel bush and pedal body, the simple solution is the remove the pedal, take out the alu spacer and sand or file down the pedal body about 0.5mm so the inner alu spacer is proud of them again, and the bolt can be properly tightened.