Originally Posted by
IPassGas
Yes, hydraulics are different, but the thread was discussing standard rotors. Steel is a poor heat conductor versus Al, so the mass relevant to the heat capacity is approximately just the outer disc mass. The floating rotor helps this, which was why they were introduced. But hydraulics are complicated for a touring/breakable bike.
When we fly with our Ritchey the brakes come off and are packed in plastic bags that prevent a leak (never have had that happen) from fouling anything else in the case. It is no more bother than dealing with cables on my solo Ritchey. It is maybe 5 minutes to install them. There are people who make quick connect fittings for the motorcycle racing world, and I have considered them, but they don't seem worth the cost at this time. Maybe if I switch to a drop bar bike I will get a set.
I have no personal experience with cable disc brakes because as much as I consider myself a bottom feeder, I am not a platypus which only eats the rotten muck at the bottom of the pond because it doesn't have gastric juice to digest real food. Cable disc brakes are about cost cutting, and they are a step too far for me.
Steel is not as good a conductor of heat as aluminum. And stainless steels are mostly rubbish. Carbon steel is a lot better, and I don't care about rust spots on a brake rotor.
But if carbon steel is not good enough, let's pretend that somebody makes a rotor with a steel working surface on an aluminum core. Hmmmm. If Shimano makes it , it is a mainline product. Now, just maybe, if they want better conductivity they could use the silver / aluminum alloy that Harley - Davidson used in their XR750 race bike engines. That stuff could frighten the devil. Wilwood makes coated aluminum rotors for cart racing and if I have any issues with the vented Hope rotor overheating I will talk to them about using one on the Ritchey.
Also, my memory of the reason for floating rotors was to reduce heat distortion by keeping the whole rotor closer to the same temperature, not to carry heat away. The vented Hope rotors and the Shimano IceTech rotors are both aimed at moving heat away from the rotor surface.