TheFedExpress

Hey guys. So a couple weeks ago, I bought a new 2014 Giant Roam 2 from my LBS.

Recently, I've been noticing some buzzing sounds coming from my front brakes and only my front brakes. The sound occurs when I'm traveling fast (from going down a hill, or just pedaling really fast) and I engage my front brake. If I'm casually riding and engage my front brakes, I don't hear the buzzing noise from my front brake.

I have the original brakes on my bike, and the full specs of the bike can be found here: 2014 Giant Roam 2

So, would any of you possibly have a clue what the issue with the front brake might be? Should I worry and rush the bike over to my LBS ASAP? I would really appreciate any input.


Note: Sorry I can't provide any specific speeds. I don't have any cycling computers to measure how fast I'm traveling on my bike. If it helps, I'm a novice biker who averages 12mph over 20 miles (very rough estimate from a map and timing my ride).

Wanderer

I suspect there is some sand embedded in the pads. Clean the pads and rim surfaces, and see if it goes away. Alcohol is good for this.

dynaryder

Could be something on the pads,but could also be a slightly warped rotor or the caliper could use centering.

Look down into the caliper. The rotor should be in the center between the pads. If you rotate the wheel,and the rotor stays to one side,then the caliper needs centering. These aren't your brakes,but the first part of this article will tell you how to do this. If the rotor is centered,but occasionally moves toward one side or the other,then it needs to be trued. Slowly turn the wheel until you see the rotor rub the pad. Hold onto the spokes at this spot(to remember where it is),and turn the wheel until that part of the rotor is out of the caliper. Using an adjustable wrench(DO NOT use pliers,the jaws have teeth that will score the rotor),bend the rotor slightly in the opposite direction. Repeat the process until you can spin the wheel 360 and not have the rotor touch the pads.

John Redcorn

A quick thread hijack for my own question: I just got my crosstrail disc (mech discs) yesterday. I asked the guy at the shop if there were any special concerns (re: discs) for someone like me who is always removing/reinstalling the front wheel to carry in a car trunk. He said no it's real easy (it is) and also said that discs normally rub a little. Didn't sound quite right to me. Today I went for my first real ride and when I installed the front wheel I spun it and sure enough I heard a tiny rub once per rev. I don't hear or feel anything when braking though. (I haven't had a chance to actually look at it or check the rear)

Was he BSing me because they were real busy that day (said they were) and rushed through assembling my cheap (to them) bike? Or is it actually normal? I'm a newbie biker but long-time car/truck guy and I know car rotors rub full time but never in any pronounced way at one certain spot in the rev.

dynaryder

Prolly,or he didn't know what he was talking about. I am actually amazed at how many shop folks don't understand disc brakes. I've bought over a half dozen disc bikes that had to be tweaked when I got home.

Your disc caliper is mounted down near the axle. Changing the tension on the QR will move the fork leg,and the caliper,in or out a tiny bit. This can cause rub. Because of this,you need to make sure you don't change the tension when removing/installing the wheel. Clix skewers were designed to prevent this.

If you didn't have rub when you first picked up the bike,and the brakes felt good,then try loosening or tightening the QR a little until you don't hear the rub. Make sure you don't loosen it too much,it still needs to be properly tight. In the future,when removing the wheel,count how many turns you spin the QR,and in what position you had the lever. When you reinstall the wheel,put the lever in the same position and spin it closed the same number of times. This should give you the same amount of tension and prevent rub.

TheFedExpress

Thanks for the input guys. I'll look into what y'all said. But is there any reason that I can only hear the noise when I'm braking from fast speeds?

dynaryder

More speed means stronger vibrations when applying the brakes.