| Also playing devil's advocate, I wouldn't expect the grease monkey at my local bike shop to know the exact grade of steel used in the outers as much as the grade of alloy use in the centres either. This guy obviously sells brake discs and sells lots of them, and does he really need to know the composition? You should try phoning your local bike dealer, ask the same questions and see what response you get - they'll only read it out of the product brochure! |