Shiamno XT brake squeal
Shiamno XT brake squeal
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plfrench

Original Poster:

4,305 posts

291 months

Tuesday 16th June 2009
quotequote all
Sorry, the search facility hasn't been working for a couple of days and I couldn't see anything after a few pages of looking back through...

I have recently changed to discs, and the first proper ride I had with them was on Sun at the Marin Rough Ride. They made a horendously loud squealing sound which was a bit embarrassing on the longer, steeper descents!!

Is there any way in which this can be quietened down? They're 2009 Shimano XT, 180mm front 160mm rear.

Cheers,

Paul.

Pablo16v

2,696 posts

220 months

Tuesday 16th June 2009
quotequote all
In my experience Shimano disc brakes seem to squeal more than others although I've had similar problems with older Hope M4's. There can be a number of issues that cause this.

1. The pads may have been contaminated or have a glazed surface on them. Take them out an rub them with sand paper to remove any surface glazing. It's harder to get rid of ingrained contamination but baking them in an oven can sometimes cure this otherwise try new pads.
2. The pad material can make a difference. Sintered pads tend to squeal more than organic pads. I've also found that sintered pads glaze more easily unless you get them up to higher temperatures fairly often.
3. The caliper might not have been aligned properly when fitted so the pads may not be contacting the disc dead square. This is easy to sort. Remove the pads and with the wheel in place the disc should line up in the middle of the caliper. If not it needs to be adjusted.
4. The disc rotor might need a good clean. Get hold of some rotor cleaner or achohol medical wipes and give them the once over.

From my previous experience it's always been one or two of the above that caused the squealing. I have had people tell me to rub a small bit of grease on the pad backing like car mechanics do but I've not had to do that myself.

Hope this helps.

Nick_F

10,598 posts

269 months

Tuesday 16th June 2009
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A little Copaslip on the backs of the pads - and check that the caliper bolts are torqued correctly.

plfrench

Original Poster:

4,305 posts

291 months

Tuesday 16th June 2009
quotequote all
Cheers for the replies guys. Shouldn't be contamination as they were new, but I'll check the alignment and torques.

Spacekadet

863 posts

205 months

Tuesday 16th June 2009
quotequote all
If all else fails, Hope do a disc mount facing tool which your local bike store should have.


When i was a mechanic i used this numerous times on various bikes and got great results.