Originally Posted by
Racing Dan
Shimano rotors tend to be a complex construction of a alloy spider, rivets and and a sandwich brake rotor. All with different temperature expansion coefficients. Im sure a simple 6 bolt, single piece, stainless rotor would be less prone to warping.
Shimano offers inexpensive one piece rotors
Shimano claims the three layer rotors (aluminum core between steel plates) with aluminum carrier manage heat more efficiently
because aluminum dissipates heat better than steel - I'm going to side with the Shimano engineers