Juddering front brake

stowei

I am running a cable-operated Shimano front disc. It has started to judder and I can't work out why. It's not very old so its not that the pads are worn out out and it was OK when I fitted it new. The disc doesn't appear to be warped (although to be honest with a single piston I can't see why warp should be an issue - although as I say it seems flat anyway). Any thoughts?

Thx

Ian

bobmij7

judder?? any other description?
could it be loose disc bolts? loose caliper?

http://www.pinkbike.com/photo/1346326/

Flurry

sticky patch on disk?


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[}:)]
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stowei

In terms of judder it is just like whenever I have had a warped disc on a motorbike - continually grabbing and releasing. But as I say the disc doesn't seem to be warped and anyway I can't see why that would effect a single piston set up in the way it is a problem with an opposed piston hydraulic design.

I don't think it can be a sticky patch because it seems to be a several times per rotation but an interesting observation and I'll recheck that. I can't feel anything if I bruash my fingers over the disc.

I've rechecked all the bolts and they are all sound.

Ian

clarkson

maybe you need to tighten the headset? this causes a juddering effect when braking. i presume you feel the judder when riding along rather than when not on the bike?

I said hit the brakes not the tree!!
My GT
http://www.pinkbike.com/photo/1315543/

stowei

Thanks again but no it is definitely the brake and not the headset. The 'grab' part of the grab and release symptom is sufficient to actually lock the brake momentarily if the surface is loose.

To try to throw some more light I'm going to swap the front wheel with one from one of the other bikes in the family stable (which works fine). The other wheel is from an Avid cable set-up and it has the same rotor diameter as on the bike with the problem, but a very different hole pattern - the disc on the Avid rotor seems to be more holes than metal. Because the rotors are the same diameter, is the switch safe or will the Shimano brake pads jam in the larger Avid rotor holes?

Ian

prian

Loose pads?

Trailstar
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by LongHair</i>

I got asked out[^]... by a dude[:(], Oh how my girlfriend laughed at me<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">