Uberbike's floating disc rotors provide consistent and quiet braking at reasonable weights, and are as resistant to warping as any we've tested.
Regular rotors are cut from a single piece of stainless steel, but floating rotors use a steel braking surface attached to a separate carrier. The carrier is aluminium for lightness, and the two pieces are joined with circular dowels - the idea is to reduce the tendency to warp. One-piece rotors have little choice but to twist as they heat at the edge, whereas floating designs allow for a consistent expansion.
Originally designed for motorcycles, where large solid discs had to be thick to combat warping, and thus very heavy, floating rotors have fewer gains to make on mountain bikes. Uberbike's discs are a regular 1.8mm thick - 0.1mm thinner than a solid Avid G2 rotor, and 0.05mm thicker than we measure a Formula SL to be.
The 180mm disc weighs 130g. The two main parts are tightly mated, and there's no rattle at all. Paired with a set of Avid's X0 Trail brakes, these discs feel excellent. Response is smooth, crisp and quiet, and an improvement over some standard discs.
They're also available in 160mm and 203mm sizes, and come in 10 colour combinations.