Tighten the hex nut as tight as you can with your fingers, then tighten the through bolt tight. Now back off the through bolt about an 1/8 turn, if you watch the rotor carefuly you will see it move slightly. This has been the perfect setting for all of mine , as for cleaning your choice of solvents followed by compressed air!!!!
Ps do not lube after cleaning!!!!!!!!!!!!!!!!!!!!!