Squealing Front Brakes

[alanroy]

I recently forked out over £700 on a decent touring bike having renewed an interest in cycling. I have to say I'm dismayed to the point of selling my bike if I have to put up with the dreadful squealing of the front brakes any longer. Cycling down the Limpley Stoke valley today, my squealing brakes were louder than the train whistle that was echoing around the valley at the time.

Internet sites tell me about toe-in and toe-out but not how to remedy the problem. I've scrubbed the rims clean, I have bent things, I have even filed down the blocks (only to decrease the braking efficiency) all to no avail. Throughout my childhood from my first little bikes through to my Raleigh Chopper and racing bike, I have never ever had a problem like this. After spending all this money I expect better. The bike in question is a Ridgeback Voyage World. If anyone can explain what to do about this in simple terms I would be most grateful. As it stands however, I shall simply not bother anymore and go out in the car instead.

[Baritono]

Hi Alan. Bit unsure of how to pitch this as you sound like a fairly experienced (former) cyclist who has already tried and researched various ways of dealing the problem.. but I'm not sure what you've tried beyond your comments about bending things (what were the 'things'?) and cleaning the rims.. maybe you could expand a bit?
Be assured though with bike problems, while some can be easily sorted by having the right bit of knowhow, some common or less-common problems can leave heads scratching - or a myriad different approaches depending on who is inspired to comment and add their tuppenceworth. Brake squeal will at least be partly due to setup (positioning of pads, alignment and mounting of brakes themselves, types of brakes, rims and pads..) which can certainly be tweaked, but I'm sure there are folks on here who have solved it with a twist of a spanner, and others who have long since given up on finding a cure for their own personal squeaks.. give us a shout and let us narrow it down a bit though. To start with, what kind of brakes (model, design), and what pads, does your bike have? I assume it was all set up for you when you bought it and the squealing was present from the start, rather than as the result of any changes you've made.

Regards

Baritono

[531colin]

To stop brake squeal, the sequence of things to try is this;
1 clean the rims (you did this)
2 "toe in " the brake blocks. This means when the front of the block touches the rim, the back of the block is 1mm. off the rim.
3 try a different make of brake block - lots of us like Kool stop
4 -starts to cost money- try a different make of brake- lots of us like Tektro CR 720

Squeal is basically a resonance set up when the frequency of the block gripping/releasing the rim matches the resonant frequency of a component. So if toe in doesnt fix it by altering the block/ rim interaction, theres nothing for it but to change something.
Squeal is a pain, but not insurmountable.

[CREPELLO]

2 "toe in " the brake blocks. This means when the front of the block touches the rim, the back of the block is 1mm. off the rim.

Forgive me for pointing out that this description is counter intuitive, unless you think about it really hard.
By toeing in the blocks , you're making the rear end (as in rear of bike) of the the blocks touch the rim (by 1mm or so) before the front end.

[Gearoidmuar]

SOME brake blocks squeal when running in.
One of my bikes is a Thorn Raven with Rigida Andra Rims (Tungsten Carbide) and the special Swissstop Blue brake blocks that go with these. I was warned that they would squeal for quite a while, which they did (for about 1000 miles). After that they became silent, but the lack of wear of both components, and the braking, are unbelievable.

[531colin]

2 "toe in " the brake blocks. This means when the front of the block touches the rim, the back of the block is 1mm. off the rim.

Forgive me for pointing out that this description is counter intuitive, unless you think about it really hard.
By toeing in the blocks , you're making the rear end (as in rear of bike) of the the blocks touch the rim (by 1mm or so) before the front end.

I set my brake blocks so the end of the brake block nearer the front of the bike hits the rim when the end of the brake block nearer the back of the bike is 1mm. off the rim. As far as I know this is generally called toe in. I didn't invent the terminology. How do you set your brake blocks?

[Mick F]

....... How do you set your brake blocks?

I set mine parallel, in accordance with the instruction manual.
http://www.campagnolo.com/repository/do ... -07-06.pdf
"Adjust the brake pads so that they are centred in height in relation to the braking surface of the rim and parallel to it horizontally and vertically."

The thing with toe in, eventually the block wears parallel anyway, and you have re-toe them.

[Edwards]

Mick you use Dual Pivot brakes, these I have found do not suffer any where near as much from squeal as the Cantilever type where the arm sits on a post.
I have found setting my Cantilever brakes not to squeal a pain. That was until I bought a little gadget that sits between the brake block and the rim. It has a raised part at one end and sets the front at 1mm with the rear 2mm from the rim. The gadget comes into its own when fitting the type of brake block the has the stud fitting.
This makes keeping the toe in set easy as it is done when adjusting for wear of the blocks.

The bad news is I bought the thing over 15 years ago, so do not know if you can get them now.

One thing I have done is to use a very thick grease on the pivot in an attempt to dampen any movement there. Some times it helps.
Edit for typo

[CREPELLO]

2 "toe in " the brake blocks. This means when the front of the block touches the rim, the back of the block is 1mm. off the rim.

Forgive me for pointing out that this description is counter intuitive, unless you think about it really hard.
By toeing in the blocks , you're making the rear end (as in rear of bike) of the the blocks touch the rim (by 1mm or so) before the front end.

I set my brake blocks so the end of the brake block nearer the front of the bike hits the rim when the end of the brake block nearer the back of the bike is 1mm. off the rim. As far as I know this is generally called toe in. I didn't invent the terminology. How do you set your brake blocks?

The opposite way round. The Koolstop pads even have a little plow tip (toed in) on the leading edge to have the same effect. This plow tip clears the crud off a wet wheel very nicely - one attribute towards Koolstop's being kinder on rims. I know this isn't addressing the squealing effect, but doesn't your way of toeing in encourage rim crud to creep under the rim/pad interface and increase wear?

I must admit to not trying your way of toeing in, but there may be something in it for reducing squeal. I'll have to thing about it I'm intrigued!

So how do others 'toe in' (If 'leading edge' is defined as that meets the rotating wheel first)

[enigmatic]

Toe-in means leading (front of bike) edge hits first. Pressure on the brake and friction with the rim then brings the rear into line. If you don't have toe-in then - especially with less rigid calipers - the front of the pad can lift off the rim by a miniscule amount and start a harmonic motion which causes brake judder or squeal.

http://www.sheldonbrown.com/brandt/brake-squeal.html

[Mick F]

Mick you use Dual Pivot brakes, these I have found do not suffer any where near as much from squeal as the Cantilever type where the arm sits on a post.

I've not always had DP brakes, and even now, only the front is DP, the rear is single pivot.

I'm going back to the 1960's here with chrome rims too. I've had centre-pulls, cheap and nasty no-name side-pulls, but I've never had cantis.

The ONLY time I've ever suffered from squeal is when there's been some contamination on the rims.

[Edwards]

Mick what I was trying to get at is. Being the wise sage that you are I could not imagine you ever using the engineering nightmare that are these pains called Canti.
I forgot about the clever move of single pivot to avoid the rear wheel locking up.
As you put they most brake squeal because of wheel contamination
Canti brakes can even squeal with different types of forks fitted on new bikes. Carbon fibre I think.
If I could avoid them I would, but on 2 bikes I want to use Ergo levers so at the moment am using them. I might look again a extra deep drop dual pivot or mini v's to get rid of the Canti's. They are to much messing about for me.

[Mick F]

Wasn't there a thread a few months back about squealing brakes when CJ suggested that brakes that have hangers high up tend to tighten as you brake as the frame/forks flexes? This causes the front brake to tighten and loosen repeatedly and resonate.

Maybe that's the problem?

What sort of brakes does the OP have?

Just answered my own question!
http://www.cyclexpress.co.uk/Products/World_Voyage.aspx
Looking at the picture, it seems to appear as CJ suggested. Therefore it will squeal by design.

[531colin]

Wasn't there a thread a few months back about squealing brakes when CJ suggested that brakes that have hangers high up tend to tighten as you brake as the frame/forks flexes? This causes the front brake to tighten and loosen repeatedly and resonate.

Maybe that's the problem?

What sort of brakes does the OP have?

Just answered my own question!
http://www.cyclexpress.co.uk/Products/World_Voyage.aspx
Looking at the picture, it seems to appear as CJ suggested. Therefore it will squeal by design.

No This refers to fork judder with a flexible steerer (carbon., titanium) and high cable stop. Cure is fitting an up hanger.
The bike illustrated has an up hanger, and probably a stiff, strong steerer. And the complaint is squeal, not judder.

[531colin]

God help alanroy trying to sort this mess out. No, on second thoughts, I will help.
Alanroy, there are several people here saying the same thing. They are me, Edwards, Enigmatic, and the reference to Sheldon Browns website. Hint ; Go with the herd.