I just installed new steering head bearings and races on my yz400. I thought installing a new lower bearing on the triple clamp was going to be tough because it is a press fit and I don't have a press. I put the lower triple clamp and steering stem (they are pressed together) in a plastic bag in my freezer over night. I greased up my new bearing and put it under a heat lamp for about 20 minutes. They literally dropped right together.