I have a rear hub from a Yamaha XT500 that I'm preparing to have some machining done. I need to machine the 40mm wheel bearing bores out to 42mm. What is the recommended interference fit for a wheel bearing? I'd like to have a definite diameter to tell the machinist. I know that I could get an idea by measuring the the hub that I have, but I'd rather hear the official number. I tried looking it up using machinist literature, but not being a machinist myself, it was like a foreign language.