Brake problems still!

Simonbt · Nitrous Nuisance Joined: 10 Mar 2005 Karma :

My front brake still pulses Sad

I replaced all the seals and rubbers on my caliper so it floats properly and it got a little better. The problem is that when the wheel was shotblasted i think he erroded the pillers that the disk sits on and it doesnt sit flush. I have tried getting it true by sanding down the pillars but i cant get it spot on!

Does anyone know where abouts near or in sheffield i could get the wheel trued up or if there is a little trick to get it right. Its driving me mental! i cant get it through an mot when its like this Crying or Very sad

ZRX61 · Victor Meldrew Joined: 05 Nov 2003 Karma :

Sounds like a litany of fuck ups, why was the wheel shotblasted instead of the normal bead blasting??
& why weren't the mounting surfaces masked off before it was blasted?
Probably going to have to be machined flat again in a lathe & then the pillars will be too short so the disc won't line up correctly with the caliper anyway..
How much run out is there on the disc? measure it with the caliper removed..

theshmoo · Bottomless Pit Joined: 23 Jun 2004 Karma :

Talk to a precision engineer with a work shop my dad use to do things like that a few years ago they should be able to tell if your discs are true and help you.
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CBR 1100 blackbird.

Simonbt · Nitrous Nuisance Joined: 10 Mar 2005 Karma :

I have no idea how he shot blasted it, i just know he did before he powder coated it. There is about 1 mil of runout of the disk. But after turning the disc on the pillars the warp stays in the same place on the wheel (if you know what i mean), ruling out a warped disk (its brand new from ebc)

Slinn84 · Scooby Slapper Joined: 20 Apr 2004 Karma :

1mm is way too much run-out
check your spec, the maximum run out is usually 0.2mm

my thundercat starting have brake pulsing problems and i measured the run-out precisly to be 0.3mm so it dunt take much difference to be noticable

have you tried using different discs? the pillars might be ok and it might be the disc thats warped.

Simonbt · Nitrous Nuisance Joined: 10 Mar 2005 Karma :

When i was measuring the run out (a very basic way) i taped a pen to the fork and looked at the gap as i span the wheel. I put a little bit of tape on the wheel where the disk moved. Next i took the wheel off and undid the disk. i turned the disk through 180 deg and did it back up again. Next i put the wheel back on and tested where the disk moved again. If the disk was warped you would expect the movement to be opposite where i marked with the tape but it was in the same spot.

Even if i have to post the wheel somewhere to get it trued up does anyone know anywhere?? pleeeeeeaaaase! Look at this thread about the bike in photos and you'll see how much work went into it just to have this happen Evil or Very Mad

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

One thing it could be is the front wheel bearings. If these are badly fitted then they could cause odd problems. Check that the bearings are OK, and check that the spacer is in position in the middle of the wheel between the bearings.

All the best

Keith
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