Rim brake squeal - at wits end

[SpokeyDokey]

Bike: Giant TCX1 with TRP CX9 Linear Pull Brakes.

Have tried everything to shut the front brake up - very loud squeal on long descents or simply when grabbing a handful.

Have tried toe-in, toe-out and flat with all four of these blocks; stock TRP's, Jagwire, Swisstop Black and finally Koolstop Salmon.

Still squeals.

Rims are clean. Fork is a meaty looking carbon affair. TRP say it may simply be the rims. Giant say they have not heard of the problem.

Any bright ideas please, my own thoughts are that I can:

Throw bike against wall and scream - came close today!

Get some new wheels - anyone have any experience of this curing brake squeal?

Get a new fork, wheels and run a disc brake on the front.

Go back to dealer and do deal for a different bike (mine is only 4 months old.

All PITA options but will consider anything.

All suggestions gratefully recieved.

 

[spacecat]

Is there any play in the caliper arm at all? I suppose this might cause the squeal

 

[Kies]

You have changed/adjusted everything but the wheel/rim ..... That's your problem.
Ask the shop to ket you borrow a front wheel for a quick 5 miles

 

[SpokeyDokey]

Is there any play in the caliper arm at all? I suppose this might cause the squeal

Checked this with the very helpful TRP guys and caliper is ok - basically there should be no lateral movement on the pivot which there isn't. Also boss bolts are tightened down to spec'.

 

[SpokeyDokey]

You have changed/adjusted everything but the wheel/rim ..... That's your problem.
Ask the shop to ket you borrow a front wheel for a quick 5 miles

Yes, tried everything - there was a little play in the headset too and I have adjusted that out.

 

[SpokeyDokey]

Just a thought - do all rims come with little grooves in these days instead of being smooth?

Could these be causing a problem?

 

[Rob3rt]

Just a thought - do all rims come with little grooves in these days instead of being smooth?

Could these be causing a problem?

No, but they often come with some form of wear indicator, of which this groove sounds like one example method.

 

[HovR]

Just a thought - do all rims come with little grooves in these days instead of being smooth?

Could these be causing a problem?

Many do. They're the wear marker. When you can no longer see the groove, think about replacing your rims. As above, if you have a friendly LBS I'd see if they'll lend you a front wheel for a test ride to see if it eliminates the issue. If it does you can buy it off them.

 

[spacecat]

Can't see the grooves causing a problem ..........am at a loss.........maybe its an occillation being set up simply by that brake, fork and wheel combo. Is it possible to add or take away a washer or two to alter the position of the calipers slightly in relation to the fork.

 

[P.H]

Take it back to the shop you bought it from and ask them to sort it out. If you have only had it four months any fault is deemed to have been there from the start and it's their responsibility to sort it out.
I had it on a bike I built up, I couldn't cure it and ended up swapping wheels with another bike, the new wheel didn't squeal and the squealing wheel was silent on the other bike. I'm not even going to attempt to understand it.

 

[lpretro1]

This ocasionally happens and it is down to some rims with whatever you try just keep squealing. Try Aztec pads - for me they usaully (???) stop it.

 

[SpokeyDokey]

Emailed LBS who is a really good guy and he has suggested that we do a wheel swap. Great service replying on a Sunday.

Thanks for all your responses.

Will update when sorted as it may help someone else.

 

[Globalti]

Does it squeal whichever way the wheel is in the fork?

 

[Mr Haematocrit]

I can induce brake squeal on all my TRP brakes by using non TRP pad carriers.... are you using non standard carriers?.... what model brakes do you have?

 

[SpokeyDokey]

Does it squeal whichever way the wheel is in the fork?

Not tried that - I will.