Noisy disc brakes?

Swap notes about technical issues

Moderators: Philip Whiteman, Andy Terry

Post Reply
User avatar
AlanW
Posts: 1259
Joined: 31 Dec 2007 13:55
Real Name: Alan Weaver
Location: Who knows......

Noisy disc brakes?

Post by AlanW » 15 Jan 2016 07:56

It’s a fairly common problem I know, but I have tried everything to stop the dam things from squealing and whining on my MTB. My efforts so far, tried three different types of pads, sintered, Kevlar and resin, cleaned discs with very fine wet and dry and then wiped down with brake cleaner. Even replaced the discs for brand new ones. Re-centred the calipers so many times I’m thinking of replacing the Allen screws for wing nuts now!

Tried boiling/steaming the old brake pads, even tried holding them over a gas flame to burn of any possible contamination, to no avail

But no matter what I try or do, the results are always the same. It’s okay for a few miles then back comes the squealing noise under braking, wet or dry conditions and not even harsh braking for that matter. Plus, its not like it’s a cheap brake set either, it Shimano XTR.

I’ll be honest, I have no idea what I could possibly try next. What I find strange, and I am sure that there must be a clue here, but for years I had used sintered pads and did not have any issues what so ever. But even with new pads and discs, the problem returns in a very short space of time?

And it’s for this very reason that puts me off buying a road bike with discs
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"

User avatar
Andy Terry
Posts: 903
Joined: 20 Nov 2006 14:27
Real Name:
Location: Bromsgrove, Worcs

Post by Andy Terry » 15 Jan 2016 08:49

Will the frame take cantis? :wink:

User avatar
AlanW
Posts: 1259
Joined: 31 Dec 2007 13:55
Real Name: Alan Weaver
Location: Who knows......

Post by AlanW » 15 Jan 2016 09:03

Andy Terry wrote:Will the frame take cantis? :wink:
I shall ignore that comment.... :wink:
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"

User avatar
Philip Whiteman
Posts: 2045
Joined: 19 Nov 2006 16:17
Real Name:
Location: Drayton, Worcestershire

Post by Philip Whiteman » 15 Jan 2016 09:14

Have you tried wearing ear plugs or placing a woolly muffler around your brakes?

More seriously though, I have been told about people oiling their brakes to reduce this squeal. Obviously not a sensible idea.
Last edited by Philip Whiteman on 15 Jan 2016 10:48, edited 1 time in total.

User avatar
CakeStop
Posts: 1258
Joined: 17 Nov 2006 21:57
Real Name: Steve Smith
Location: Birmingham

Post by CakeStop » 15 Jan 2016 10:20

I'm not getting too much squeakiness with SwissStop organic pads. I haven't tried sintered yet, waiting to wear the current organic set out. They occasionally squeak a bit after the bike's had a clean and I've wondered if it's due to WD40 residue on the discs. My guess is that you clean your bikes more often than I and possibly that you're more liberal with the WD40?
Eat cake before you're hungry

User avatar
AlanW
Posts: 1259
Joined: 31 Dec 2007 13:55
Real Name: Alan Weaver
Location: Who knows......

Post by AlanW » 15 Jan 2016 10:43

CakeStop wrote: ..... I and possibly that you're more liberal with the WD40?
I'm a Mr Sheen man myself when it comes to cleaning frames to be honest, and I always drape a cloth over the discs before spraying anything.

But that said, while I have been conducting the anti squeal tests the bike hasn't been cleaned which rules out any possible contamination issues
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"

GaryK
Posts: 19
Joined: 13 Sep 2014 17:06
Real Name: Gary King
Location: Lost again !

Post by GaryK » 15 Jan 2016 16:56

It's normally caused by vibration from the back of the pads the same as vehicles. A thin smear of copper grease on the back of the pads where they contact the pistons normally cures brake squeal.
The cause isn't normally the contact surface between pad and rotor so boiling cleaning etc will have no effect.

http://www.halfords.com/motoring/engine ... grease-20g
Nothing compares with the simple pleasure of a bike ride!

User avatar
dweben
Posts: 277
Joined: 22 Jan 2011 23:52
Real Name: Paul Watkins

Post by dweben » 15 Jan 2016 17:08

Whenever I get this realigning the calipers always sorts it. In the wet they just squeal not much you can do about that short of dragging brakes on descents to warm them up

User avatar
AlanW
Posts: 1259
Joined: 31 Dec 2007 13:55
Real Name: Alan Weaver
Location: Who knows......

Post by AlanW » 15 Jan 2016 20:05

GaryK wrote:It's normally caused by vibration from the back of the pads the same as vehicles. A thin smear of copper grease on the back of the pads where they contact the pistons normally cures brake squeal.
The cause isn't normally the contact surface between pad and rotor so boiling cleaning etc will have no effect.

http://www.halfords.com/motoring/engine ... grease-20g
Good tip, hadn't thought of that Gaz and l already have some copper grease. Off to the garage it is then...
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"

User avatar
AlanW
Posts: 1259
Joined: 31 Dec 2007 13:55
Real Name: Alan Weaver
Location: Who knows......

Post by AlanW » 15 Jan 2016 20:06

dweben wrote:Whenever I get this realigning the calipers always sorts it.
Yep done that countless times, even tried the two business card trick. Okay for a while and back it comes....grrrrr
"You only need two tools: WD40 and duct tape. If it doesn't move and it should, use WD40. If it moves and it shouldn't, use duct tape"

Post Reply