brake judder >&g...
 

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[Closed] brake judder >>>>> certain death?

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The >><< are a joke before anyone slates me.

Went out this morning and have sever judder on the front with little stopping power and the same on the back.

New pads and rotors both from xc racer (quaxar rotors, alligator pads). Pistons reset at time of installation.

Any ideas or should I just face the fact I am going to die?


 
Posted : 26/01/2013 12:54 pm
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Unless they are at least 200 mm rotors on the front you WILL die, judder or not


 
Posted : 26/01/2013 1:04 pm
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How does your headset feel?


 
Posted : 26/01/2013 1:11 pm
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killwillforchips - Member

How does your headset feel?

Guess the same as Ashley, hates the judder and thinks its about to die.


 
Posted : 26/01/2013 1:25 pm
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Contaminated rotor?


 
Posted : 26/01/2013 2:17 pm
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I havent checked the feeling of the headset. Seriosuly though I thought that first off and felt fine.
Someone was telling me today its because im using aftermarket rotors in formula brakes, but that struck me as odd.

Thought about contamination also but they were running fine when I put them on thursday for a ride (although lacking power as they wernt bedded in). I was thinking that somehow I have polished the rotors if that makes sense so need to sand them off?


 
Posted : 26/01/2013 4:49 pm
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Had problem with juddering on front and found rotors were not compatible with calipers. The pads were catching the rotor arms causing the judder. Worth a look though didn't suffer from lack of power.


 
Posted : 26/01/2013 4:56 pm
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I've used similar rotors in a few brakes, sometimes they work, others they judder horribly. Some rotors are worse than others in some brakes. And power is always down whatever brand of lightweight rotor.


 
Posted : 26/01/2013 7:47 pm
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That will really pee me off If ive spent 40 £ and they are not compatible!


 
Posted : 26/01/2013 8:54 pm
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I've had that recently too - start by giving pads and discs a good clean before replacing parts.


 
Posted : 26/01/2013 9:47 pm
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check the bolts and the disks are fitted the right way round, try clean pads and disks with IPA, maybe sand a little of the pads and try bed them in again!
you can use a felt pen to draw a line across the disk to help see where the pad edge comes to on the surface of the disk.

EBC pads FTW


 
Posted : 26/01/2013 9:52 pm
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ps check life insurance policy upto date... 🙂


 
Posted : 26/01/2013 9:53 pm
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Gas mark 7 and cook them, pads that is,


 
Posted : 26/01/2013 9:56 pm
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Dales what about fan assisted ovens?

Will give them a clean and a sand or a sand and a clean. Something to do tomorrow night!


 
Posted : 26/01/2013 11:26 pm
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I had this with some cheapo pads that rubbed on the arms of the rotor by <1mm.

Cured it by removing the offending bit of each pad with a junior hacksaw and a stanley knife, problem solved.


 
Posted : 26/01/2013 11:35 pm
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Oldnick how did you establish where it was rubbing? I know the answer will be really simple but got to ask!


 
Posted : 27/01/2013 9:37 am
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You will see the marks on rotor arms.


 
Posted : 27/01/2013 2:26 pm
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Bit of engineering I'd guess.
Measure outside of rotor to top of pad friction material.
Pad out
Place pad on rotor, look through rotor and mark position of arm.

Mind dont know how Nick did it, working a tape measure is a difficult thing for him 😉


 
Posted : 27/01/2013 4:28 pm
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Wavey formula rotors by any chance?


 
Posted : 27/01/2013 4:38 pm
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if the pads rub on the rotor arms it might be better to use a spacer washer to move the caliper out a bit instead of cutting the pads, unless the pad is wider than the braking surface of the disk


 
Posted : 27/01/2013 4:44 pm
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I have had this in the past... was using superstar discs in Formula RX calipers. went back to Formula ones and it was fine.


 
Posted : 27/01/2013 6:53 pm
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They are quaxar floating ones as listed on xcracer. Please note not slating his service or the product as service has been brilliant.

Going to have a play, see if the pads are hitting the arm. Which maybe a possibility.


 
Posted : 27/01/2013 8:00 pm
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It was the shape of the disc that was causing the judder I reckon... Not the quality of the superstar product.

The ones I used were the saw shaped variety and the gaps in the outer most circumference were to blame. Looking at the quaxar they are similar in that they have wobbly outer.


 
Posted : 27/01/2013 8:07 pm
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i have formula wavey rotors have used them for years, on 32mm stantioned forks with long travel the ewavey rotors cause the brakes to grab on the thick part of the disc...and it makes the forks flex, don't notice it on 36mm forks or short travel or if u swap the rotor to the rear.. change the rotor to a conventional one and the problem goes away. why formula insist on varying the braking surface is beyond me as it has no positive effects.


 
Posted : 28/01/2013 9:04 am
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Just had a look at the rotors. It appears I have escaped unharmed, from the pads catching the rotor arms.

But I dont have any washers to space out the calipers.

Dammit!


 
Posted : 28/01/2013 8:08 pm

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