Hi Chris.

I wouldn't go there. When we tried to use the F&P as a motor on our solar car I remember we had lots of problems, and gave up after several months of trying. It was easy enough to get it to spin, but speed control and back emf were the killers.

But if you were to use one, I think the plastic hub would be fine for strength. Remember it can spin a full load of wet cloths up to 1000rpm in a few seconds.

I would go for the Oatley 450watt motors and their speed controllers. A couple of these motors on a little go kart would go like the clappers! Oatley also sell chains and sprockets to suit.

You know what would be cool. 4 motors, one on each wheel. The 300 watt motors are a lot cheaper, give you 1200 watts total, and 4 controllers, all tied to one hand throttle. The kart would have some serious acceleration. 

Glenn