squealing cantilever brakes

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Jurassic2
Posts: 11
Joined: 26 Sep 2017, 10:19am

squealing cantilever brakes

Postby Jurassic2 » 13 Oct 2018, 12:51pm

Anyone able to offer any advice on "squealing cantilever brakes" so far tried two different sets of pads, cleaned and degreased the rims (several times) and toed in as well.
This is on the front brake only, but net result, still squealing was hoping to use this bike (Galaxy) as my winter commute, but becoming a real pain and starting to fall out of love with her....

Any assistance abd advice, what else can I try ?

Brucey
Posts: 34233
Joined: 4 Jan 2012, 6:25pm

Re: squealing cantilever brakes

Postby Brucey » 13 Oct 2018, 12:57pm

what model of brakes do you have?

In particular do they have integral pivot bushings (part of the arm assy does not rotate) or does the whole arm assy rotate around the boss on the fork itself?

Photo of your setup?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

rmurphy195
Posts: 1339
Joined: 20 May 2011, 11:23am
Location: South Birmingham

Re: squealing cantilever brakes

Postby rmurphy195 » 13 Oct 2018, 3:52pm

Could be worn pivots, you shuold be able to check for this by simply trying to wobble them!

If the canti's have their own internal bushes that form the pivot bearings, with the inner bush held tight against the mounting post, easier to fix by just replacing the cantis.

If the canti's pivot directy on the mounting posts, could be interesting to sort out.
Brompton, Condor Heritage, creaky joints and grey hair
""You know you're getting old when it's easier to ride a bike than to get on and off it" - quote from observant jogger !

PH
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Joined: 21 Jan 2007, 12:31am
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Re: squealing cantilever brakes

Postby PH » 13 Oct 2018, 5:27pm

Some people have reported using an uphanger reduces or eliminates squealing and improves braking.
https://www.spacycles.co.uk/m2b0s101p18 ... ver-Brakes

Jurassic2
Posts: 11
Joined: 26 Sep 2017, 10:19am

Re: squealing cantilever brakes

Postby Jurassic2 » 13 Oct 2018, 10:07pm

Thanks PH, looks like it's worth trying at £6 + a bit of p&p guess if it's mounted to the fork it reduces the cable length and may be the flex

landsurfer
Posts: 4613
Joined: 27 Oct 2012, 9:13pm
Location: Rotherham

Re: squealing cantilever brakes

Postby landsurfer » 14 Oct 2018, 7:39am

Jurassic2 wrote:Anyone able to offer any advice on "squealing cantilever brakes" so far tried two different sets of pads, cleaned and degreased the rims (several times) and toed in as well.
This is on the front brake only, but net result, still squealing.


+1 Exactly the same issue with my Jamis Aurora, fitted with Tektro 992 cantilever brakes .... and again, help !
“I’m responsible only for what I say, not what you understand.”

The Road Goes on Forever.

pwa
Posts: 9602
Joined: 2 Oct 2011, 8:55pm

Re: squealing cantilever brakes

Postby pwa » 14 Oct 2018, 7:45am

I know the OP has cleaned the rims, so this may not be relevant in this case, but I find any hint of chain oil on a rim causes squealing brakes. And I find plain old washing up liquid in very hot water does a better job than solvents (white spirits) at getting it off. It takes five minutes of easy work to do this so it is worth a try.

I've used an uphanger for years and on my bike it cured juddering. No idea how, but it did.

landsurfer
Posts: 4613
Joined: 27 Oct 2012, 9:13pm
Location: Rotherham

Re: squealing cantilever brakes

Postby landsurfer » 14 Oct 2018, 7:54am

Maybe the up hanger is the answer, note the unsupported lengths of the brake cables front and rear on my Jamis.

IMG_2831.JPG


Up- hanger ordered ...
“I’m responsible only for what I say, not what you understand.”

The Road Goes on Forever.

pwa
Posts: 9602
Joined: 2 Oct 2011, 8:55pm

Re: squealing cantilever brakes

Postby pwa » 14 Oct 2018, 7:57am

landsurfer wrote:Maybe the up hanger is the answer, note the unsupported lengths of the brake cables front and rear on my Jamis.

IMG_2831.JPG

Up- hanger ordered ...


I reckon its an upgrade for any bike with cantis, it doesn't cost much and installation is not much more complicated than normal recabling. You do need new cable of course.

landsurfer
Posts: 4613
Joined: 27 Oct 2012, 9:13pm
Location: Rotherham

Re: squealing cantilever brakes

Postby landsurfer » 14 Oct 2018, 8:24am

pwa wrote: You do need new cable of course.


I'll fit an in line tensioner and use it to extend the current cable.
“I’m responsible only for what I say, not what you understand.”

The Road Goes on Forever.

thirdcrank
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Joined: 9 Jan 2007, 2:44pm

Re: squealing cantilever brakes

Postby thirdcrank » 14 Oct 2018, 9:05am

Jurassic2

It's up to you, of course, but I'd recommemd responding to Brucey's post

Brucey
Posts: 34233
Joined: 4 Jan 2012, 6:25pm

Re: squealing cantilever brakes

Postby Brucey » 14 Oct 2018, 9:08am

IME uphangers have a good track record of curing judder but don't fare so well at curing squeals. The reason is that squeals are usually generated by movement (of small parts at high frequency) in a plane that is pretty much at right angles to the cable. Uphanger or not these movements may persist.

By contrast judder occurs when the fork is able to resonate fore and aft when the brake is on and there is some feedback for brake pressure with fork movement. With a conventional hanger this is the case for sure but even so most bikes with conventional hangers don't judder; this is because it takes a driving force of some kind (braking not even because of a problem in the brake/rim, wheel not round, not balanced etc) eg when the wheel is turning at the same frequency as the forks will resonate. An uphanger doesn't cure these issues, but does lessen their effects.

If/when you buy an uphanger, it is as well to give a passing thought to whether/how you want to fit a front light. Dynamo lights are often best mounted on the fork crown but this is made less easy by the presence of a standard uphanger. IIRC there are some uphangers which include (or work better with) some light fittings.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

PH
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Re: squealing cantilever brakes

Postby PH » 14 Oct 2018, 10:13am

As it's the front brake and not the rear, it might be worth the 10 minutes to swap them round. Though it's also possible that by doing something from scratch you find a solution without ever having diagnosed the problem.
If you're not using STIs then I'd give converting to Vs some thought, it's not ridiculously expensive and IMO they are the easiest brakes to live with.

Jurassic2
Posts: 11
Joined: 26 Sep 2017, 10:19am

Re: squealing cantilever brakes

Postby Jurassic2 » 14 Oct 2018, 3:49pm

Hopefully image attached:
Image Attachments
IMG_20181014_152704.jpg
IMG_20181014_152709.jpg

Brucey
Posts: 34233
Joined: 4 Jan 2012, 6:25pm

Re: squealing cantilever brakes

Postby Brucey » 14 Oct 2018, 6:47pm

Tektro Oryx; these brakes have integral pivot bushings. Are they worn? Maybe try swapping front and rear brakes as suggested upthread?

Some things that make squeals worse with these brakes;

-that the bosses are not tight where they thread into the mounts (if they are removable type bosses)
- that the M6 bolt that holds the arm on the boss is not tight
- that the integral bushings are worn
- that the integral bushings are not lubricated.

The arms have a front cap that is a push-fit into the inside of the arm bushing. This cap is also retained by a little Loctite. With care these caps can be pushed out and the integral bushing can be disassembled, cleaned and relubricated. If the bush is badly worn, you can (temporarily) alleviate the wear by wrapping few turns of PTFE tape around the bushing before reassembling it. 'Temporary' in this case often means a few months.

Changes of brake block/alignment can also stop squeals, but it isn't an exact science.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~