Stop crank bolts loosening

The best way to get a good fit is this:

1. Put the cranks on
   
2. tighten to the stated torque
   
3. take an easy ride for about 100 yards
   
4. then re-tighten to the stated torque
   
5. repeat parts 3 & 4 but increasing the intensity of each subsequent ride until the bolt/crank on longer moves up the taper.
   
   
   

NEVER DO THIS !

NEVER !

Ask a metallurgist about metal 'bruising' - this method is a really bad idea and an often repeated crank mounting myth (for want of a better phrase).