Brake squealing

[Matt2matt2002]

Thanks Mick.
Do you think that the facf I have swapped the pads front and rear and the squeal is still coming from the front, indicates the rim is the cause?
No squeal ever on the back.
I've toed in the pads to various degrees ( & no degree! ) but no change. Always a squeal on the front.
White spirit to clean the rims.
Pads are brand new.

Rough them up a bit? Well I guess I could but I can't get away from the ' front only' ever squeals. So doubt it's a pad issue.

How long should these CSS rima last? I've no idea how old they are.
Should they feel rough or dead smooth?

Thanks for you thoughts

[mickeg]

I already saw they were new pads and the white spirits.  I do not know what white spirits is, but i suspected that is the same as Coleman stove liquid fuel. 

I can't imagine that a CSS rim would be the fault.

Usually rim brake rims wear out when they get too thin to hold pressure.  Has not happened to me but one of my neighbors said that a few years ago when he was braking and slowing, it felt odd, like part of his wheel was fatter than part of it, he could feel it in the brake lever.  And very soon after that the rim blew apart.

But CSS rims have a surface that does not wear down to that extent.

I used to have some cantilever brakes on my Nomad rear, could not get rid of the squeal, eventually switched to V brakes and the squeal went away.  In your situation where the squeal started after switching to new pads, that suggests to me that the fault is somewhere in the new pads or as you noted the pad holder.

I have no ideas other than what I already mentioned.  Although I saw before that you tried a solvent, I still would try the soap and water if nothing else seems to work.  Since any lubricant contaminating a brake can cause squeal, that is why I suggested the soap.

Since nobody else is throwing out other new ideas, looks like the crowd has run dry on ideas on what else to try.

[Matt2matt2002]

Thanks Mick
Yes, I guess it's going to be a mystery I'll have to live with. A bit like ' life '!
Toe ing in cured past problems but no luck with this one.
Strange that swapping the pads front to back doesn't cure the issue.
I wish I knew the age of the rims but having bought the bike second hand....

Once again, thank you for your thoughts.

[bobs]

How about borrowing a front wheel or putting the wheel into another bike. Failing that don't use the front brake🤔

[geocycle]

I don't think the age of the rim will be a factor.  It is true that the CSS surface does rub away and there is a school of thought that a shift to softer blocks might help braking, but I don't see how it would result in a noise. Is the braking still smooth? Is there any sign of rim damage or have the sides flared at all? Borrowing a front wheel would be an interesting experiment.  Potentially easier would be to experiment with brand new cheap blocks first.

[John Saxby]

experiment with brand new cheap blocks first

Or, you might try Kool Stop pads, which is what I use. These are not quite as expensive as the Swisstop pads.  SJSC's offerings are here: https://www.sjscycles.co.uk/search/?term=Kool%20Stop%20brake%20pads

I've had no squealing problems with Koolstops on my Raven's (Shimano) V-brakes. (Rims are alloy, with machined faces.) Had some squealing with my derailleur bike recently, with KoolStop pads in Avid canti's,  but the squeal disappeared when I eased off the cable tension.  That modulated the pressure.

I realize that this suggestion is a recommendation to swap parts, not really a product of analysis, Matt, but it might work.

[mickeg]

I think this is what John was suggesting.
https://www.sjscycles.co.uk/brake-blocks/kool-stop-r16-v2-v-brake-inserts-ryde-rigida-css/

I use these because the Swiss pads were not in stock at SJS when I bought my CSS rims.  But I have had an occasional squeal out of these pads.  I have never tried the Swiss pads, so I can't offer a comparison.

But these look different than mine, it appears that they make a change to the part of the pad that presses on the rim.

[Matt2matt2002]

Out with 2018 and in without a squeal!!

Yeeha!

No more squealing.
It had become a real pain and no fun.
Ok - it can be a good warning in lieu of a bell or horn - but seriously - it was BAD.

I had swapped the front and rear pads ( no squeal from the rear - ever ) but it was always on the front. Probably more nearside.
I had toed in. I had toed out. Flat as well - but no luck.

I'm using CSS rims. How old? No idea but the bike is 10+ years old. It's second hand to me - and came in good condition - but no idea about age of parts.
I put on new Blue Swisstops and after a few months the squeal began.
The bike had been knocked over while parked and one theory was that the fork 'stork' that the brake assembly (XTR) slips onto, had been bent.
 ( What's the proper name for the stork? )

Another theory ( mine ) was that the shoe sleeve'groove that holds the brake pad was wobbly.
The T shape was not rigid. It flopped about a bit. Perhaps this caused the squeal?

But no - the new replacement ones I purchased from SJS were the same.
I had wanted to slip the blue Swisstop pads into the replacement shoe sets.

I didn't bother when I saw they were 'floppy'.

However, in desperation at the horrendous noise - today I fitted the Shimano Brake Shoe Set - M70R2
And squeal has gone.

Thoughts and opinions folks.....

The rim feels smooth. Is there any way of telling if it's times up? Should it feel rough?
The rear has a different feel. Not so smooth.

Any problems likely to arise from running none Swisstop type pads on a CSS ( worn ) rim?

Whatever 2019 brings - it will be a quiet blessing.

Happy New Year to you all.
From a very peaceful Matt

[mickeg]

If the CSS rim feels smooth, I do not think you can wear them out from brake wear so it probably only means that it will not work as well when wet..

Since it is smooth, just keep using your Shimano pads but occasionally look at the pads to make sure they are not wearing fast and look to see if any of the pad material is sticking to the rim. 

But I would not recommend a non CSS pad on a rougher rim since a rougher rim would be like using sandpaper on regular pads.

I was curious what would happen with regular pads when I first tried my brand new CSS rims.  I went a couple of km with regular pads and found that I was building up a residue of pad material on the rim.  So, I immediately installed the Koolstop CSS pads.  (When I ordered my frame and rims, SJS was out of stock on Swisstop pads, thus I ordered the Koolstop pads.)

[Matt2matt2002]

Many thanks for previous replies and advice.

The squeal persisted and I have only managed to find the solution.
It is a CSS rim with ordinary pads.
The noise was stopped by placing the pads to grip on the very edge of the rim nearest the tire.
It appears that the CSS coating has worn away at the normal part of the rim.

Fingers crossed this is the solution.

Thanks again folks.