Bicycle Mechanics - Disc Breaks rubbing

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Hello,
I am notably a new rider, I purchased a 2009 Fuji Neveda 1.0 Moutain bike this year, and noticed after a few rides the brake rotors are rubbing a little. This is espeically noticable with the front as I had to remove the wheel to get the bicycle home. Is this rubbing somewhat normal? A relaitive of mine bought the exact same bike, and he had similar issues.. .I've also noticed the disc breaks do not seem to grab quick. I have an older BTM bike w/ V breaks and the seem to brake faster or grip better than my disc brakes.. Are these brakes just breaking in, or do they need adjustments?
Thanks, jR
The discs should break-in within about 100 miles or so. If you still find they're not gripping or engaging well, you might have to use the barrel adjuster to fine-tune how soon they engage in relation to how hard you press the levers.
One of the PITAs about disc brakes, is their tight adjustment tolerances. If you remove the wheel and don't keep the skewer tightened exactly the same as it was previously, you're at risk for throwing the calipers out of alignment with the disc. You can experiment with the skewer tightness by adjusting the nut in small increments to get the brake back in alignment; however, sometimes it's easier to make a minor adjustment to the caliper centering. Typically, you just loosen the bolts that fasten the caliper horizontally, squeeze the brake handle, and retighten while still squeezing.
FWIW, my best advice is recenter the brakes, buy a bike rack for your car, and don't take the wheels off. :)
cooleric1234
09-16-09, 09:05 PM
One of the PITAs about disc brakes, is their tight adjustment tolerances.
I just bought a mountain bike and I must admit after working on road brakes (both caliper and linear pull) disc brakes are a huge pain to adjust. After following all the steps, taking whatever sensible advice I could find online, and repeating ad nauseum I just couldn't get my brakes to not rub and grip quickly. Finally I determined that the brake rotors must have been ever so slightly bent even though they were new (two sets of brakes - I even bought some BB7's because I thought they would fix the issue). After getting so frustrated that I took an adjustable wrench to the rotors I found that did the trick. They were only out of true what seemed like a mm or so, but the mechanical advantage is so great on these things that that was enough. Anyway, maybe they stop well but I now hate disc brakes. My advice is to first follow all the adjustment procedures you can find online, and only then try to see if the rotor wobbles a little.
operator
09-16-09, 11:32 PM
Brakes.
Brakes.
But it's a Neveda instead of a Nevada, so it might actually have breaks :P
norwood
09-17-09, 05:37 AM
I think it has breaks, peddles and a gooseneck.
davidad
09-17-09, 08:13 PM
If it's an Avid cable operated caliper Park tool has an article on them. There is a knob on the caliber that sets the pad spacing.
operator
09-17-09, 08:16 PM
I think it has breaks, peddles and a gooseneck.
Haha, good one
If it's an Avid cable operated caliper Park tool has an article on them. There is a knob on the caliber that sets the pad spacing.
Yes, the brake is cable operated. I did manage to get the rubbing to stop. I searched thru a few other threads on here discussing how the wheel needs to be adjusted just right, if not it can cause the rotor to rub. I also noticed the rotor is just slightly warped. So I took the wheel out and set it back in and adjusted the wheel until I got the rotor to line up evenly between the brake pads.
Now wheel and brake seem to be operating fine, for now, I was concerned however; when I pull the brake, and the pads clamp together it causes the rotor to pull, or bend to the side. Is this normal? Thanks again, I will hopefully mess w/ adjustments once I get the rest figured out.... thanks.
I was concerned however; when I pull the brake, and the pads clamp together it causes the rotor to pull, or bend to the side. Is this normal?
That's normal for mechanical disc brakes as only 1 pad moves, when you apply the brake the outside pad moves inwards and pushes against the rotor which is then pushed inwards till it rubs against the inside pad. When the brake is disengaged the rotor will spring back and move away from the inside pad.
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