Hey all….

So I finally found a bike that I wanted, a 2012 Giant Anthem X1. It’s awesome and I’m very happy…. Apart from the horrendous squeal the rear brake makes. So I’ve googled lots and read in forums about this but eventually couldn’t sort so took to the bike shop.

SLX brakes with 160 Avid Rotors.

Sanded lightly and cleaned, still squeal.
Replaced pads, still squeal.
Replaced pads and rotor, still squeal.
Replaced pads and rotor and full SLX brake system, still squeal.
Replaced pads, rotor, full brake system and a borrowed rear wheel!!!

STILL SQUEAL!!!

The complete rear was taken off and all bearings checked…

Guess what…..

STILL SQUEAL!!!

The frame looks ok with no visible faults. I have contacted the seller (which I dislike doing) and before he dismantled the bike he rode it in October with no faults. It was stood until I bought it last weekend. When I tested it the squeal was there but we thought the brakes just needed bleeding.

A week later, a lot of money being chucked away and no improvement at all.

Even the cycle shop is confused so they are calling Giant on Monday.

Anyone any constructive theories?

All the best, Sooty.

Check frame brake mounts (if not already done, they should have done it)

it’s possible I once came near to them, every brake I’ve ever touched instantly becomes irrepairably squeaky. The only solution for me is to not care 😆

Is Sweep trapped in the rear triangle?

Ear plugs?

Youve got contaminated fingers

I would suggest you reface the brake mounts on the frame using the correct tool, this may help

Frame is obviously possessed by a pig. have you tried holy water?

Have you bedded in the brakes properly or just ridden round the block?

Have you tried magic water?

Is this all the time, or just when applied?

Have you tried a different brake?

Tiny bit of Copper grease on the back of the pads and between all shims if you have them and also on all threads

Swap to shimano rotors. Problem solved.

What carlos said.

Is Sweep trapped in the rear triangle?

😆

Although I’m still annoyed I expected replies like this and they making me smile… But I’d really like to enjoy my new bike without annoying everyone I ride with!

The rear calliper bolts straight into the frame on the Anthem.

Pour coca cola over disks and leave for a while then ride, accelerate and brake hard then repeat, while singing the coca cola song.

You may wish to ignore the singing part.

+1 for having the disc mount re faced.

Out of interest how do you align your pads?

Tried complete new SLX kit including pads, wheel and rotor!

If the rear mount is miss assigned a new brake will make no difference.

Out of interest how do you align your pads?

Just to split a hair: it’s the caliper that one aligns, not the pads. Pardon me if that’s what you meant.

Hope video does a good job of describing caliper alignment…

[video]http://www.youtube.com/watch?v=akIWGqEE0PY[/video]

I adjust my calliper to align my pads if youre being that picky.

+1 for facing the mounts.

Have you checked the rubber hub bearing seal? Mine was dry and squealed like a pig, a small smearing of grease sorted it.

I’ve had this on my slx brakes – after a lot of fannying around it turns out they’re very sensitive to alignment. I spent ages aligning them and they no longer squeal.

Rubber hub bearing seal?

Apologies but I’m new to all this!

I’m not sure how to adjust the mounting bracket as the calliper is bolted to the frame?

As for the coca cola…. My mate suggested the same thing! Can of coke at the ready!

Ill try post a pic of the calliper.

Stop giving a shizz, problem solved. Or GT85 straight on th disc.

Swap from organic to sintered or vice versa? I had a real problem on one bike with sintered. Made a nose like an angry goose. Semi organic/ kevlar made it only happen in the wet. Oh and swingarm bearings checked or replaced?.

Cheers for the video post. Will try that now.

What avid rotor is it thre was a bunch of stuff about avid rotors and resonance not that long ago which avid responded to by re-doing the rotor with less groves.

Maybe the Shimano brakes are having the same issue as the elixirs had in the past?

Edit, just seen your pic with a roundagun rotor, don’t think they were the affected ones, however cross brands may yield the same issue.

How is your pad wear with that rotor, it looks kinda low against the caliper?

The bike shop changed everything!

Even borrowed a wheel!

Ill take pics of rotor and pads….

Conversely my slx set up with XT discs it’s pretty quiet, bar in the wet.

Avid says A17 JUN 11 160MM HS1

Pads say Shimano L F296 R F294
Both F03C METAL

I would say check everything is tight, calliper bolts, rotor bolts, QR – and make sure all threads are lightly greased.
and if your lbs can face the post mount get that done as noise comes from vibration and if its not square then the pads wont be making great contact.

Are the post mount bolts the right length? I recently replaced a friends brakes and the mounting bolts were minusculely (not noticeably) longer than they needed and the brake squealed when tested. Took a while to work out as the bolt did up tightly and it looked like a snug fit.

Finally tracked it down to the bolt length, filed a couple of mm off the bottom and problem solved.

Although I doubt very much it’d work, it’s cheap and quick to try:

how about some washers made from an old inner tube in the mounting bolt “stack” above & below the caliper – might just dampen any vibrations ?

This is the weird thing, the PO has been fantastic and is helping as we go…

He rode it in October and no squeal at all.

It then stood till last week when I bought it. The PO had it tightly packed in his boot with both wheels and saddles off. When he put the bike together and I rode around the rear brake squealed like crazy and WOULDN’T stop me. I could pedal through the tightest of pulls. Thinking it just needed bleeding I took it to my bike shop and all this happened! Lol.

The power is there now, but not like the front. The front is amazing!

Confused.com!

Get Sue to have a look at it for you

1)has it only ever had the mismatched brake/rotor? Or have you tried a Shimano rotor with it?

2) some time spent making sure the 2 pistons are pushing evenly is worthwhile. I’ve had Shimano brakes centred by the usual method, where they’re actually working more like a cable brake – with one pad pushing the rotor over into the other. Holding back the enthusiastic piston to let the other work its way out sorts this.

CHANGE THE ROTOR TO SHIMANO! !

Check the hose isn’t resonating. Never had it myself but read about it happening to a specialized full bouncer in a mag, may have been MBR. Sounded a bit odd to me but you could try adding some zip ties to the hose to ensure it’s secure. Seems like you’ve tried everything else.

That being said you say the rotor was changed but that’s not a shimano rotor in the pic, this seems to be causing some confusion.