Giant Defy advanced 3 - NOISY DISC BRAKES

defyman

Hello folks,

I have been riding my son's Decath Triban for 3yrs. Been happy on it but its 2 sizes to big for me! Treated myself to a new 2016 Giant Defy advanced (carbon) 3 with spyre cable operated discs. Riding the same rural roads Ive always ridden I'm hearing a lot of clatter from the disc brakes whenever I hit poorly surfaced areas of tarmac. They're noisy enough to make other cyclists look over their shoulders. The faster I go, the louder the noise. The dealer has looked at the pads and said the noise is normal for discs on a road bike. My MTB with hyd discs on the road makes no noise. In a effort to help I've fitted 28 conti gatorskins at 80 psi but its made no difference. I don't feel like im riding a premium bike - I asked the dealer for a comfortable ride.

So my question is if you have a Giant Defy with disc brakes or any road bike brand with discs do they rattle with a high pitched noise? Does anybody have a road bike with disc brakes that are silent.. ..which is what I was expecting on mine!

Thanks in advance!

veronese68

I think it may be that as you have cable discs the pistons are pulled back by the mechanism and there is a gap between the disc, pad and piston so the pad can rattle between the disc and the piston. You could try adjusting the clearance so it is as tight as possible, it may help. The MTB with hydraulic discs doesn't make the noise as the pads are always just off the piston as the pads are pushed back by the disc turning and there is no big spring pulling the pistons further back.
Also I'm not familiar with spyre calipers but is there no ant rattle spring between the pads? My old BB7s didn't rattle but there was a soft spring clip thing that would push the pads against the pistons very gently. The 3rd piece in this picture:

Man Of Lard

Giant Revolt here with TRP Spyres and coming from a hydro disc MTB they are a lot less forgiving of inaccurate setup.

If your brakes are squealing - that usually happens to me if I've wound the pad adjustment screws in a midge's whizzer too far (done ¼ turn when only ⅛ needed) or that I've swapped wheels and the calliper is no longer perfectly aligned with the disc. For that - loosen off the calliper mount bolts by ½ turn, jam the brake on hard and tighten the bolts back up.

Rattling on the other hand - not had it happen to me - but that would imply that the pads are maybe not being held off the discs by the (crappy) spring (definitely there on mine when I bought it) that is supposed to push them back...

defyman

Thanking all for comments.
Yes there is a spring between the pads. Playing with the spring now its easy to 'twang' and rattle. I'm wondering if i placed little rubber discs there it would dampen the noise down. There again I'm loathed to tinker around on a new bike. The dealer has been good and said I can change bike to another brand, but I'm so wary of disc brakes now, I fear I may have the same problem again. The noise has been sufficiently loud to spoil the riding experience. I spent over a grand - the dealers has tried to be helpful and I didn't want to put them out any further especially as they tell me that its only me whos complained.

cycleclinic

contaiminated pads and rotors is another cause. Really the shop you bought it from should sort it. Just sorted the howl from my wifes bike. I had a faulty caliper changed that) and contaminated pads and rotors. I changed those as I dont have the time today to clean up the rotors and pads (the pads maybe to contaminated to save).

Pad/caliper alignment is key too. My spyres are quiet. I get some noise from sintered pads when it is wet.

defyman

I agree dealer should sort out as bike is still just 3 weeks old, but hes had a go twice. They said they had tested it too. However when I went riding with a friend who confirmed the noise. May I ask you if you've heard the same noise when riding fast on poor road surface sounds like bottles rattling on a milk float!