they are on our tandem with 203mm rotors 4 piston Shimano deore calipers. right now I am trying a basic sram rotor. they are glazing just from going down a 18% grade thats about 1.5 blocks and keeping the speed at 25mph. the tandem is heavy around 400 pounds but this is only 20 or 30 seconds of braking. maybe 3 or 4 times. week. only on the back too. these are MTX ceramic pads. I had al little of this on an ice-tech rotor but that was from longer decents a lot longer. the scratch was from the ice-tech rotor when it was worn. the thing is we have a 5 degree slope we go down every time we ride and if I use the back brake the whole way down it works normally till the next day and I have to repeat it.
