My XT Disc brakes will not stop squeeling, dry or wet weather!
I've cleaned the discs, sanding the pads, baked one set of pads, swapped pads from front to rear.
Which worked for about 20mins of riding!

Pads are the original pads that came with the set, guessing they are sintered?

I was talking to Merlins about this, they mentioned that the frame may not have been faced perfectly, then they mentioned facing the mounts.. mounts for the disc brakes??

Does anybody have any suggestions on how to silence the bitch?

Clean the rotor thoroughly, take pads out and rub the friction surfaces across each other to remove any glazing.
Refit pads and try again. Go for a muddy ride as that'll help deglaze them too.
Failing that check the wear on the pads, if its even across the whole pad then the mounts are ok, if one edge has more wear than the others, mounts may require facing.

Thanks

Is it difficult to face the mounts? is there any guides on how to do it?

you need an expensive tool – I'd contact a local bike store to get them to do it.

Is it difficult to face the mounts? is there any guides on how to do it?

It's not a DIY job. It has to be EXACT and the tool is about £250..!

LBS should charge £10-£15

Thanks Peter,
This leads me on to my next question… can anybody recommend a bike shop around hemel hempstead hertfordshire?

Are they still stopping you as well as they should?
I,ve had Shimano brakes that have leaked fluid onto the pads. Not enough to be obvious but enough to dull the braking performance and make them howl.

Alternatively, are you running a 180mm disc at the rear? There could be just enough flex in the frame and leverage at the mount to set up a resonance under braking. I had a 180mm Magura on a full susser which howled everywhere from new until I changed to a 160mm rotor and adaptor. It's been silent ever since.

They do stop me well, i can sit down brake and launch the back end up into the air..

I've got a Giant Anthem X2 2009, XT M775 2009 Disc brakes 180mm Rotors F+R
I used to have Hayes stroker rydes with 160mm rotors F+R but they were pretty lame..

Looks like i have a few options, new pads, or new 160mm rotors, or new pads + 160mm rotors..

are both pistons working properly?

my thoughts would be recentre the calliper to disc and try new pads.

never had a disk mount faced yet…

I had the same problem with my XT's, I'd recently changed the pads – I don't remember the brand but they weren't Shimano. Got some new Shimano ones and they were fine afterwards.

Changed the brakes a couple of weeks later 🙄

Golddigger ,if you can`t cure the squealing and need to have the mounts faced try Addiktion cycles in St Albans.

One of the better shops locally.

This leads me on to my next question… can anybody recommend a bike shop around hemel hempstead hertfordshire?

Try Ben at Revolution Cycles over in Harpenden: http://www.revolution-cycles.net/

dan

Thanks guys, thanks jolly Green Giant for recommending Addiktion cycles..
Think ill try some new pads first, then if that dont work nip over to addiktion and get their opinion…

Thanks

try some organic pads usually a hell of a lot quieter than sintered, although even the sintered ones should not be squealling in the dry!

You don't need to face mounts with shimano discs – no need to do that. What others have said about pads.

Another low cost bodge is to put a dab (small) of copper grease on the back of the pad where it interfaces with the piston. It may or may not make a difference but it usually works to cure squeal on a car.

I've tried the copper grease trick.. didnt make any difference..
Can anyone recommend any pads worth trying?

Discobrakes organics are worth a try.

Edit: Hmm, they do not seem to do them anymore….my bad.

just bought some ceramic pro c compound pads from disco, claim to be virtually silent, made by a non metallic compound, not actually used them yet but they are a similar compound to resin or organic but suppose to be silent. Check out disco brakes i have the same brakes as you so i know they have them in stock!

Interesting – my stroker rydes on my x2 are pretty lame and was thinking of doing the same upgrade

Rock… the XT's give so much more power, but the squealing is annoying!
If the squealing can be mutted then i recommend them..
I got mine from merlins for £200 for the complete set..

Im wondering if the 180 rotors i put on are the problem, looking at this years Anthem X2 it comes with XT disc brakes and 160mm rotors..curious if they used the 160mm because of this..
http://www.giant-bicycles.com/en-GB/bikes/model/anthem.x2/4892/39050/

angaio – Member
You don't need to face mounts with shimano discs – no need to do that.

Er, why? Can Shimano guarantee all frames have true disc mounts?

Avid Tri-align is supposed to get around this but its a pain to set up.

goldigger, get your mounts faced, it ensured your pistons are parallel to your disc along all axis, not just when you look down at them.

Scruff when you say mounts, do you mean the mounts on the suspension fork and rear frame or the shimano mounts that bolt on to the frame?

One thing i have noticed is that everytime i take the front wheel out the pads never align with the rotor when i put the wheel back in..

Anyone used superstar pads?
http://superstar.tibolts.co.uk/index.php?cPath=21&osCsid=18d2a19b6a0b19c4db659b8c5e70d188

I found that the problem with mine were the stock shimano pads that came in them. Changed pretty much straight away to some basic disco pads and all have been fine ever since. I also have some SLX that come with different pads to the XT's and they've been silent too.

I'd definitely try new pads before having the faff of getting the mounts faced.

Are these the disco pads i need? the ceramic pro's?
http://www.discobrakes.com/?s=0&t=0&c=14&p=125&

Cheers

Edit..I've ordered these

they proabbly use 160mm rotors to save weight, its uaualy quite a weight difference going upto 180mm, and its an XC bike not a DH bike. I run 160/180 which is more than enough unless your really pushing it downhill.

thisisnotaspoon
Im confused why your reminding me why my X2 is not a DH bike, did somebody say it was?
I bought 180mm front and rear as thats what i wanted on my XC bike… 180mm will give me that extra stopping power i wanted.. i had 160mm on originally and didnt like them..

Discobrakes ceramic pro pads turned up today.. thoroughly cleaned my rotors with mug off brake disc cleaner, popped the new pads in and gave every bolt on the calipers a tweak. 20 miles off road and hardly a peep out of them, the only time I got a squeal was when bombing it down a track covered in tree routes and small jumps slightly out of control..
Thanks for recommending the discobrakes pads guys.. 🙂