Well the discs were around 1 month old, and done around 500 miles, so should get away with buying the one disc.
Where did you get the disc from?
Ahh good point, I don't want the other too do the same. I can't remember where I got them from, I think it was at a show a while ago and fitted them around a month ago.
Im not sure what broke first though, the disc or the caliper.
Ben