7 maybe 10 I doubt..
but that largely depends on the weight it has to move tbh.
I'd say you're much better off finding a 350W pregeared my1016 with matching controller to achieve a 10mph goal reliably.
check the
calculation thread..
and you'll see that my best guess for a 10mph goal will be around 160-180Watts at least
adn you do not want to run at peak power constantly sooo 350Watts is certainly a good size for a lightweight contraption(and rider)
'sid
PS Wrong Forum, I'll move this thread