If you've got a "floating" disc... that won't work! If you don't, that should be your next mod...full floating discs.Yeah... I've had a few thoughts this afternoon. Maybe a small "puck" to hold a laser pointer to the disc brake surface (magnetic maybe). It could then be moved around to point at the other side. It would be nice to have the laser alignment be "hands free". Probably need to measure run out of the disc.