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FZS600 Fazer / Front Brake judder
« on: 27 August 2015, 03:35:56 pm »
Hi all,
This might be a bit of a read so stay with me! I've done the usual searches but not come up with much to help me. The bike is a 2002 fzs600 with 30k milesish.
The problem is a pulse through the front brake lever while applying the brakes, it happens at all speeds and appears to be once every rotation of the wheel. It is enough of a judder to make the mirrors vibrate and generally be very annoying while riding. I don't use the brakes that often but even with light pressure the lever pulses.
The problem began a while ago. I had taken apart the front end of the bike for various reasons, cleaning, upgrading etc. There was no pulse before I took it apart. While the bike was in bits I: had the front wheel powder coated, lightly sanded and painted the forks myself, fitted new bearings in the wheel and new sbs ceramic pads in the calipers. I reused the standard discs. Not long after I had it back on the road I noticed the pulse through the lever and it has been driving me a bit mad...
So things I have already done to try and solve it are:
1) made sure the mating surface for the disc carriers to the hub of the wheel were sanded/filed smooth to remove any uneven paint from the powder coating process
2) fitted brand new front discs, pads, braided brake lines to replace the original rubber ones, new fluid, new seals in the calipers and all pistons cleaned up/polished/red rubber greased and moving freely.
The pads in the left hand caliper have very small movement backwards and forwards in the caliper and by this I mean very small amount of movement but with the front of the bike jacked up off the floor if you turn the wheel back and forth then you can just hear the pads move slightly. You can also see on the inside on the caliper where the pads have worn a very slight channel into it. I have found a link to an old thread on the old site about how to modify the spring retainer for the pads to make them sit hard against the front edge of the caliper to eliminate this movement and will probably try that tomorrow.
When the front wheel is off the ground then there is a little bit of resistance from the pads as expected but there does seem to be a slightly tighter spot... Warped discs I hear you say... but how when they are brand new and when the problem was the same before with the original discs..
So the next things to try are:
1) pad retaining spring mod
2) Tomorrow I am going to tie one caliper out of the way at a time and take it for a small run to see which side the problem is on or if it is both sides that cause it to pulse.
3) Remove forks and use a file to make sure caliper mounting points are completely level and that when I painting the forks I haven't put it to thick on one mount making the caliper sit slightly squint (they look fine to the eye but guess a tiny fraction could cause a problem)
4) possibly new bearings but there is no noticeable wear on them and they've done less than 5k miles, they feel smooth to turn by hand and no vibration apart from when braking
I just don't really know what else to try and can't afford to just throw money at it. Anyone got any ideas?
Thanks,
Chris
This might be a bit of a read so stay with me! I've done the usual searches but not come up with much to help me. The bike is a 2002 fzs600 with 30k milesish.
The problem is a pulse through the front brake lever while applying the brakes, it happens at all speeds and appears to be once every rotation of the wheel. It is enough of a judder to make the mirrors vibrate and generally be very annoying while riding. I don't use the brakes that often but even with light pressure the lever pulses.
The problem began a while ago. I had taken apart the front end of the bike for various reasons, cleaning, upgrading etc. There was no pulse before I took it apart. While the bike was in bits I: had the front wheel powder coated, lightly sanded and painted the forks myself, fitted new bearings in the wheel and new sbs ceramic pads in the calipers. I reused the standard discs. Not long after I had it back on the road I noticed the pulse through the lever and it has been driving me a bit mad...
So things I have already done to try and solve it are:
1) made sure the mating surface for the disc carriers to the hub of the wheel were sanded/filed smooth to remove any uneven paint from the powder coating process
2) fitted brand new front discs, pads, braided brake lines to replace the original rubber ones, new fluid, new seals in the calipers and all pistons cleaned up/polished/red rubber greased and moving freely.
The pads in the left hand caliper have very small movement backwards and forwards in the caliper and by this I mean very small amount of movement but with the front of the bike jacked up off the floor if you turn the wheel back and forth then you can just hear the pads move slightly. You can also see on the inside on the caliper where the pads have worn a very slight channel into it. I have found a link to an old thread on the old site about how to modify the spring retainer for the pads to make them sit hard against the front edge of the caliper to eliminate this movement and will probably try that tomorrow.
When the front wheel is off the ground then there is a little bit of resistance from the pads as expected but there does seem to be a slightly tighter spot... Warped discs I hear you say... but how when they are brand new and when the problem was the same before with the original discs..
So the next things to try are:
1) pad retaining spring mod
2) Tomorrow I am going to tie one caliper out of the way at a time and take it for a small run to see which side the problem is on or if it is both sides that cause it to pulse.
3) Remove forks and use a file to make sure caliper mounting points are completely level and that when I painting the forks I haven't put it to thick on one mount making the caliper sit slightly squint (they look fine to the eye but guess a tiny fraction could cause a problem)
4) possibly new bearings but there is no noticeable wear on them and they've done less than 5k miles, they feel smooth to turn by hand and no vibration apart from when braking
I just don't really know what else to try and can't afford to just throw money at it. Anyone got any ideas?
Thanks,
Chris