Just dont make the mistake I made and forget to put that spacer in,
and the 2 small bearings. That is why my diff melted the first time
I was in a hurry because linton's big race was coming up, and
tottally forgot to...

It's fixed now though.

And the B44 hex doesnt fit the 501x, I broke it trying to tighten the front wheel of the 501x.
I was so pissed off. :/
I have new front B44 hexes on the way though.