ben
Grunt
Posts: 29
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Post by ben on Aug 5, 2008 14:05:46 GMT
Hello all, the front disc brake on my Giant Trance 3 is rubbing slightly. The brakes are Avid Juicy 3's and i've followed the instructions by slackening the mounting bolts then re-tightening while holding the brake hard on (they've got some dish shaped washers that are supposed to self adjust using this method). If I spin the wheel by hand you can hear a slight rub and sometimes a squeak when they're wet. The wheel still seems to spin for a long time but I like to think this is holding me back on hills, not the 'spare' body weight! ;D Any tips to get rid of this? thanks, ben  |
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Post by dyls on Aug 5, 2008 14:34:20 GMT
I had this problem with my juicy's as well.
Keep on slackening the bolts, squeeze the brake and retighten the bolts while holding the brake. It took me quite a few go's to get it right.
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Post by martinw on Aug 5, 2008 14:47:00 GMT
Try holding the brake lever closed tigt with a cabletie while you concentrate on tightening the caliper.
I also had the same problem with my juicy 7's drove me insane so i changed the brakes
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ben
Grunt
Posts: 29
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Post by ben on Aug 5, 2008 16:25:00 GMT
Thanks for the tips, i will give it a go again. good idea with the cable tie martin that will make it easier |
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Post by sikora on Aug 5, 2008 20:58:08 GMT
I actually like to run my Juicy 3 levers so close to the bars that they constantly rub.
I don't find it slows the bike down.......... i blame that on my fitness!!!
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ben
Grunt
Posts: 29
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Post by ben on Aug 5, 2008 22:37:01 GMT
I had another go at it and there is still a very slight rub but I can live with it, will have to see how it is after a decent ride. I actually like to run my Juicy 3 levers so close to the bars that they constantly rub. I don't find it slows the bike down.......... i blame that on my fitness!!! there goes my excuse then! ;D ;D |
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Post by martinw on Aug 7, 2008 5:48:59 GMT
I don't think the rotors are of best quality on the juicy's and I wonder wether they warp a little with the heat of braking.
I never could get rid of the rubbing on mine.
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ben
Grunt
Posts: 29
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Post by ben on Aug 7, 2008 12:46:32 GMT
I did wonder if it could be the rotor thats warped, I might take it off and see. I will be booking it in for a service at revolution cycles at some point so i will see what they think. thanks for the help, ben |
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gw8izr
Have-a-go Hero
Posts: 123
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Post by gw8izr on Aug 7, 2008 15:15:13 GMT
The material is soooo thin I'd have thought it would be possible to warp it a little if you didn't torque the rotor bolts down carefully in sequence - so I'm going to have a dable at measuring the run out on mine this weekend. I'll take my dial gauge home and report back here.
A quick Q Ben, does the rub / noise change if you fiddle with the brakes, i.e. can you make the problem go away at all?
My Juicy 3's are fine until I do a "sh1t there is a tractor in the way" type stop, then they go noisy and drag. If I play with the controls I can make the problem go away after a mile or so and they remain good until the next emergency stop.
Rim brakes.... thats the answer :-)
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Post by sikora on Aug 7, 2008 16:42:07 GMT
The material is soooo thin I'd have thought it would be possible to warp it a little if you didn't torque the rotor bolts down carefully in sequence - so I'm going to have a dable at measuring the run out on mine this weekend. I'll take my dial gauge home and report back here. A quick Q Ben, does the rub / noise change if you fiddle with the brakes, i.e. can you make the problem go away at all? My Juicy 3's are fine until I do a "sh1t there is a tractor in the way" type stop, then they go noisy and drag. If I play with the controls I can make the problem go away after a mile or so and they remain good until the next emergency stop. Rim brakes.... thats the answer :-) That sounds like a sticking piston to me. Either that or the CPS bolts on the caliper aren't tight enough |
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gw8izr
Have-a-go Hero
Posts: 123
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Post by gw8izr on Aug 9, 2008 7:52:37 GMT
The caliper bolts are nice and tight but I agree that a sticking piston is plausible - I hadn't thought of that.
Measured the rotor run out and in bicycle terms its negligible.
Now what I did find is that setting the wheel in the dropout is very critical, obvious I know but I am more used to setting up steel rod brakes :-)
I was quite close to going to rim brakes on this bike, after all it's a road bike and they are lighter / simpler, but after getting PWT in the lovely Anglesey weather this morning and seeing how good they are in the rain I'm going to stick with them.
There is definitely a small amount of air in the front brake so think I am going to investigate making an adapter to allow me to bleed them this afternoon.
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Post by Taffydoo on Aug 9, 2008 18:50:56 GMT
Hello all, the front disc brake on my Giant Trance 3 is rubbing slightly. The brakes are Avid Juicy 3's and i've followed the instructions by slackening the mounting bolts then re-tightening while holding the brake hard on (they've got some dish shaped washers that are supposed to self adjust using this method). If I spin the wheel by hand you can hear a slight rub and sometimes a squeak when they're wet. The wheel still seems to spin for a long time but I like to think this is holding me back on hills, not the 'spare' body weight! ;D Any tips to get rid of this? thanks, ben I had this problem I removed the pads and give them a bit of sand on the surface, refitted the pads and loosend off the caliper bolts and cable tied the lever. With the brake on I tightened the caliper bolts and tested and it was fine. |
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Post by Taffydoo on Aug 9, 2008 18:56:17 GMT
I don't think the rotors are of best quality on the juicy's and I wonder wether they warp a little with the heat of braking. I never could get rid of the rubbing on mine. Whats the hope's like? The rotors look very good. Give it a few months and I might invest in some. My brakes on the Marin got so hot on Conwy Mountain they were binding. They cooled down and were fine |
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gw8izr
Have-a-go Hero
Posts: 123
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Post by gw8izr on Aug 10, 2008 15:36:23 GMT
well that's fixed it.. my improvised bleeding kit worked, the joy of having a lathe .. and generally "mesing about" with them has stopped the problem.
Can't help thinking that they may have sorted themeselves out anyway after a few more miles...... but to justify making the bits I'm claiming this as a victory :-)
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Post by sunbeamgls on Sept 1, 2008 11:14:44 GMT
I've had similar problems with my Juicy 5s - seems to affect the front much more than the back brakes. This could be any one (or more) of the following:
- heat causing disk warp;
- poor aligment of the caliper;
- "wedge" wearing of the pads;
- poor alignment of wheel in the drop-outs;
- over filled hydraulics;
- sticking pistons not releasing.
Given that mine were binding after about 100 miles, I figured that sticking pistons was not the issue. Here are the steps I've been through:
- slackened off the caliper mounting bolts, rotate the wheel , pull brakes full-on then re-tighten the caliper mounts. This seems to work on only some occasions and doesn't seem to stop it happening again later.
- noticed that the problem seemed to re-occur at the beginning of rides. This seems to be because the caliper is very sensitive to being tapped or rested on when the bike is in the back of the car with no front wheel installed, so be prepared to re-check the caliper mounting bolts every time you put the wheel back in. Bit of a pain.
- had the guys at the trail centre in Llandegla take a look and they re-aligned the caliper by eye, not by pulling the brake on. Worked very well and they reckon that earlier mis-alignments leads to wedge shaped wear on the pads so even after adjustment it takes a while for all binding to disappear and needs several re-adjustments to compensate for the wedge shape disappearing over time.
- for over filled hydraulics (which can stop the pistons returning so quickly), wrap kitchen towel around / under the bleed valve on the lever, pull the lever gently and open up the bleed valve - continue to gently pull the lever until a few mls have bled out then tighten up the bleed valve. Then leg go of the lever.
Due to all this faffing and unreliability, I'm seriously thinking of different brakes, particularly up front, when the pads need changing.
Anyone got recommendations on front disks for general trail use? Hope? XT?
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