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help please, or i'm going to windmill arms my bike
Front brake pulses when braking (about 1 time per rotation of the wheel). Already changed pads, rotor, adapter, bled, aligned, etc. no change.
Noticed that there is a bit of vertical movement (1-2 mm) on the rotor, would that potentially cause a pulsing brake?
Other thing I noticed is this damage to the hub (along to the right from the top of the 0):
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Didn't notice it while fitting, so not sure how it's happened.
Looks like the holes are possibly drilled off centre on the rotor and the little tab has pressed on the lip and cracked it as i tightened the torx bolts?
what brakes - some rotor/brake designs are known to pulse a bit.
wwaswas - Memberwhat brakes - some rotor/brake designs are known to pulse a bit.
I don't want to mention the make of the rotor just yet. 🙂 The brake is SLX, old style.
The pulsing is very slow, like 1 every wheel rotation and you can actually feel it grabbing the brake much harder then letting go.
Applying the brake feels a bit like riding on an egged wheel if you've ever had that little treat.
tbh, if the rotors not actually round when mounted then I'd get that sorted before looking any further?
If it's a Superstar flame rotor 🙂
Mine does it a bit too, think it's just the design
If there's a couple of mm of play in your rotor, then that's most likely the issue. Could your hub shell be cracked?
The disc may be running off center, try loosening the disc bolts and then re-tighten while twisting the disc clockwise to centralize on the bolts.
Are they ashima rotors? They look like they might be. I've had pulsing from an Ashima rotor, reduced after bedding in though. you shouldn't be able to detect any movement in them relative to the hub/wheel though!
Edit: too late on the brand guess!
Close but no cigar, it's a Superstar 'Vibe' rotor. 🙂
Thing is, i've had a pulsing avid brake before, that was more like the vibration from an engine idling and you could [i]just[/i] about feel it on the lever.
This is much slower, and much more severe. Feels like going from 50% to 100% braking at about once per rotation.
Dibbs - MemberThe disc may be running off center, try loosening the disc bolts and then re-tighten while twisting the disc clockwise to centralize on the bolts.
Cheers, I'll try this again. Wondered if the lip which is broken is normally supposed to centre the rotor, hence it being out of alignment vertically.
honourablegeorge - MemberIf there's a couple of mm of play in your rotor, then that's most likely the issue. Could your hub shell be cracked?
not play, it's solid, but you can see it moving relative to the caliper when you spin the wheel ❓
wwaswas - Membertbh, if the rotors not actually round when mounted then I'd get that sorted before looking any further?
Yes will try to, but I think the (half broken) broken lip it's resting against will prevent it from being moved.
Wonder if the rotor has a thick spot? do you have access to an accurate measuring device? digital calipers? See if its thicker at the point it pulses.
mrjmt - MemberWonder if the rotor has a thick spot? do you have access to an accurate measuring device? digital calipers? See if its thicker at the point it pulses.
Well sort of accurate - they're ebay jobbies. No difference in thickness that I could see anyway. S'pose it'd only take a fraction of a mm to cause this.
Thanks for the sanity check on this everyone. Finally got another rotor of a different brand and the vibration has gone. Seems it was two faulty rotors (from the same manufacturer). Will be interesting to see what they say... 🙂