Phooey Posted June 22, 2015 Posted June 22, 2015 Can anyone suggest an easy method to check the brake disc runout? I don't have dial indicators or anything beyond sockets and screwdrivers etc.I ask because on the way home this evening I lifted my visor and rode really slowly to listen to a rubbing sound. When I got home I span the front wheel to hear a rubbing sound but I can't tell if it is the pads or the disc. But it is loud enough to cause concern.Any help would be very much appreciated. Quote
fq-craigus Posted June 22, 2015 Posted June 22, 2015 You may find its brake dust clogging the disc rollers. You clean them out then it will sit true and straight "> Quote
Phooey Posted June 22, 2015 Author Posted June 22, 2015 Wow! ... I though I'd take a quick look not expecting too much and found that every single roller is solid. I can't get it to move a mm with my fingers.Thanks fq-craigus. I guess I know what I'll be doing on my next day off In the meantime is it safe to ride do you think. Quote
Tango Posted June 22, 2015 Posted June 22, 2015 It should be ok for a short while.......but, yeah, you need to clean those bobbins out....... Quote
fq-craigus Posted June 22, 2015 Posted June 22, 2015 Yeah you can use not a prob but now you know what to start with just get on it as soon as you can. You will struggle to move with fingers indeed, unless your the hulk. A tin of brake cleaners and nut and bolt will see you good, time taken doing this will prolong life Quote
Phooey Posted June 24, 2015 Author Posted June 24, 2015 Just a thought. I have noticed that when the disc is cold, I only hear a slight rubbing. This gets louder and more pronounced as the disc warms up. Does that sound about right? Quote
eastanglianbiker Posted June 24, 2015 Posted June 24, 2015 check one of the calipers isnt sticking on slightly Quote
Phooey Posted June 25, 2015 Author Posted June 25, 2015 ok so update. Today I used a whole can of brake cleaner to free the bobbins. They were in a bad way - No difference. Still get the rubbing, or more like a knocking sound. Checked pads - they are not sticking. It definitely gets faster as I increase speed so is related to the circlular movement of the wheel and it seems to stop when I apply the front brake. I've checked everything I can think of but found nothing wrong. Any idea what to try next guys. Quote
Guest Posted June 25, 2015 Posted June 25, 2015 Any vibrations in the brake lever when you apply the brake?- if so, you have to change the brake rotor.Have you took out the caliper from the rotor when you clean it? The pistons goes easily back in the caliper? Have you applied brake few times whilst the caliper was out and checked if both (or how many) pistons are getting out almost in the same time? For example if you have 2 pistons and only one gets out when you are braking, then it is possible that the other one is stuck/seized mostly because it got dirt and rust under the piston seals. That means when you are depressing the brake, it won't go back in the caliper to leave the rotor spin freely.Usually a can of brake cleaner doesn't help to much if the seals are out of shape.Hope that helps ... Quote
wr6133 Posted June 26, 2015 Posted June 26, 2015 When did you last rebuild the Callipers? The Tokicos on the ZZR are a bloody nightmare for bunging up and for a piston or 2 to start sticking slightly. To keep mine not sticking after the last rebuild I now blast a bit of brake cleaner down them at least fortnightly. Quote
Phooey Posted June 26, 2015 Author Posted June 26, 2015 When did you last rebuild the Callipers? The Tokicos on the ZZR are a bloody nightmare for bunging up and for a piston or 2 to start sticking slightly. To keep mine not sticking after the last rebuild I now blast a bit of brake cleaner down them at least fortnightly. I am going to be swopping them out for Nissins when I get the time but I have checked them and they don't appear to be sticking. To be honest, it is sounding more like a knocking than a rubbing. Pity I can't find a way of recording it. I have a feeling it's the pads moving around in the calipers. But the thing that is making me doubt this is the fact that it is rythmic. And, it get faster as I ride faster and slower as I ride slower which is indicative of a circular periodic issue. Quote
Guest Posted June 26, 2015 Posted June 26, 2015 When did you last rebuild the Callipers? The Tokicos on the ZZR are a bloody nightmare for bunging up and for a piston or 2 to start sticking slightly. To keep mine not sticking after the last rebuild I now blast a bit of brake cleaner down them at least fortnightly. I am going to be swopping them out for Nissins when I get the time but I have checked them and they don't appear to be sticking. To be honest, it is sounding more like a knocking than a rubbing. Pity I can't find a way of recording it. I have a feeling it's the pads moving around in the calipers. But the thing that is making me doubt this is the fact that it is rythmic. And, it get faster as I ride faster and slower as I ride slower which is indicative of a circular periodic issue. Try to check the wheel spacer. The one between the wheel bearing and fork leg. It happened to me under havy brake to hear knoks in fork ... I discovered it was the spacer ... Just put some grease on it.Cheers Quote
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