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Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 9:16 pm
by Martin
didn't know weather to create a new topic or if i was supposed to post in my other one about the airbox.

here's my new dilemma:
im putting the bike back together, i had some new bearings installed in the wheels (car mechanic did it, he was fixing my brothers bmw so he did my wheel bearings for free).
now the wreckers sold me 4 sets of bearings when i asked for them for front and back wheels. the mechanic installed 3 and said the other one i had was too big to fit, but the bearing that was in there was fine.
so i put it all back together, new front break pads and disk rotor (well...roadworthy, from the wreckers) and now the break pads are constantly in contact with the rotor on the front wheel, is there an adjustment bolt im not seeing or something simple like that?

bit of a more odd problem on the back wheel, the caliper housing seems to be rubbing on the bolts on the rotor. the rotor bolts sit slightly proud (i haven't touched the rear rotor or pads). the piece of metal that attaches the caliper to the bike doesn't clear the bolts, and when i tighten the wheel nut (on the axle) it just closes the gap and gets worse. i thought it might be the break pads not sitting in place right, but that cant be the problem because its the caliper housing not clearing the rotor. its as if the wheel is slightly too wide or im missing a spacer or something but i cant see where!

if i cant figure this out, ill book it into a mechanic (my mate has a ute) and ill ask the mechanic to JUST FIX THE BREAKS and not touch anything else. i can do the rest. but this has really got be confused.
oh and i don't have the chain on yet either.

ill take pics in the morning if required

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 9:32 pm
by Daisy
Sounds like you're missing a spacer. Have you got a manual?

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 9:48 pm
by Martin
got a service manual, going to go through that and check side by side what ive got and what if anything im missing

edit: using this service manual http://pdftown.com/Kawasaki-GPX250-Service-Manual.html

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 10:01 pm
by hoffy
It's normal for them to just rub on the disk slightly and make a *swooshing* noise, but the wheel should still spin freely and of it's own accord when the front end is lifted up.

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 10:16 pm
by Martin
ok, but they're rubbing way too much

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 10:20 pm
by hoffy
Martin wrote:ok, but they're rubbing way too much
I would suggest taking off the front wheel and re fitting it to see what the issue is..this is easy if you have a front stand, if you dont try to hook up with someone that does, alternatively a bike mechanic will be able to tell in a matter of minutes what the issue is.

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 10:25 pm
by 6maniac
Maybe the second-hand disc is warped ?????

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 10:30 pm
by Martin
it isnt warped, as far as i can see

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 10:34 pm
by 6maniac
Doesn't have to be a visible thing - only needs to be out by fractions of a millimetre.

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 11:14 pm
by Martin
i dont have a micrometer or a vernier :(

Re: Breaks rubbing on rotor (clearance issue)

Posted: Wed Sep 24, 2008 11:24 pm
by 6maniac
If you can remove the front wheel, take it to a bike workshop - they should have the gear to check it. Imo, second-hand/used brake parts are not something you should fit unless they are known to be A1. :roll:

Re: Breaks rubbing on rotor (clearance issue)

Posted: Thu Sep 25, 2008 2:27 pm
by Martin
Daisy wrote:Sounds like you're missing a spacer. Have you got a manual?
you were spot on! i dropped a spacer on the right hand side of the wheel when i took it off, and it was lying in a fold of my dropsheet! hehe im so relieved. i put the wheel back on and its tracking so smoothly now. thanks for the help guys, i feel a little silly now

Re: Breaks rubbing on rotor (clearance issue)

Posted: Thu Sep 25, 2008 3:16 pm
by Daisy
We're here to help.
Glad you got that sorted. :D

Re: Breaks rubbing on rotor (clearance issue)

Posted: Thu Sep 25, 2008 5:40 pm
by Gazza
6maniac wrote:Doesn't have to be a visible thing - only needs to be out by fractions of a millimetre.
make up your mind 6maniac

either metric or imperial, not both :lol: :lol:

you dont want to confuse him :lol: :lol:

Re: Breaks rubbing on rotor (clearance issue)

Posted: Fri Sep 26, 2008 8:21 am
by bonester
When I put GPZ1100 rotors on my GT550, the left disc bolts fouled on the calliper. Wrecker cracked out the grinder and ground down the heads of the bolts until it was free. I have since filed the forkleg where the calliper mounts and replaced the rotor bolts. The reason for the problem was that the disc was thicker than standard. I've since put new GPZ rotors on the GT. I also had a similar problem when I fitted an Aussie Brake Disc to the rear of my GPZ900R- the disc rubbed the pad slides. I left that one and the disc wore away the offending part eventually. :shock: