I've got an '05 Stumpy FSR Comp 120 with Shimano M525 discs. After a recent ride, I noticed a rubbing noise coming from the rear brake. Upon closer examination it appears that the disc is warped - I must have hit it on a rock or something, but I don't remember having done it.
My question is this: is it worth trying to 'true' (i.e.: unwarp) the disc, or should I just replace it? If I replace it, are there any aftermarket disc rotors that are any tougher that anyone might recommend?
Finally, is this a typical failure mode for discs? Do mechanics see a lot of these types of failures?
Thanks in advance for your advice,