Buzzing Disc Brakes

[bungee]

Hi Guys, I am a relative newcomer to cycling, my last experience was in 2005 when I went over the handlebars at high speed with no helmet on. Cracked skull in 3 places, 7 x-rays on various body parts and 6 years later and I'm back on a bike this time with a proper helmet. Anyway at the end of last year I bought a new MTB with disc brakes. I have never experienced disc brakes before and none of my friends have any knowledge either. It may be nothing but when I am going at high speed especially downhill and I brake, there is a buzzing noise coming from the front brake disc its kind of like the noise that would happen if you put a piece of paper into the spokes of the wheel. It doesn't happen at all at low speeds or on the rear brake disc. Also occasionally there is a loud creaking noise again coming from the brakes at high speed so much so that I can feel the vibration through the saddle. Kind of like the noise and old bus makes when it brakes. Any idea what these noises could be ? I have taken it to Halfords where I bought it and they say the brakes need time to wear in, however I am probably on about 150 miles now. Also it has a quick release wheel which I am not sure exactly how tight to make it. If I make it as tight as possible the brake disc doesn't run smooth and there is rubbing between the brake disc and pads, too slack and the wheel will likely fall off. I'm a bit lost with it all and really don't know what is correct.

Any advice ?

 

[2Loose]

Hi and welcome.

You need to take a look in the 'Know How' section, there are plenty of threads where people have certain issues with their disk brakes if you use the search function.

Chances are that the pads are rubbing on the disk and the whirring noise is the pads running over the holes in the disk. - What type of disk brake are they, model, cable or hydraulic etc. I am sure someone can help with the right info.

PS. QR Lever should be as tight as it can be done by hand and still reach the flush with the fork position.

 

[bungee]

Thanks, i'll have a look around and see what I can find. From what I understand the brakes are Shimano BR-M445 Hydraulic Disc Brakes. I guessed the whirring noise might be the pads running over the holes but wouldn't it do it on the back as well ?

Thanks again

 

[2Loose]

It'll be the rubbing on the disk bit that causes it. Sounds like the rear is adjusted correctly, but it is easier to hear noises from the front than the rear while moving for obvious reasons.

You'll probably find that realigning the caliper on the fork (very easy to do -honest) will sort this one. Having the wheel out or loosened off may have caused it to get slightly out of line with the disk.

Make sure the front wheel is tight first.
Loosen the bolts holding the caliper onto the forks so that the caliper can move sidewards.
Squeeze the lever, release, rotate the wheel a bit and repeat a couple of times. The squeeze will make the caliper grip the disk and move sidewards to align itself properly.

Hold lever squeezed and re-tighten the bolts.

Takes 2 minutes.

 

[bungee]

Thanks, found that somewhere else eventually. Will try it later