our car is gonna be out of control after 50mph and you will be lucky to have mini tires that can even handle over 70mph.
yes, we sound like nay-sayer's ...but I've pushed various cars to the limit over the years ...you fix one thing and another problem arises.
Provided you do get metal gears (I do think I've seen them via Asiatees).
you may run into trouble with that too. I've found that plastic spur against metal pinion works best. ...I actually grinded up my metal spur and metal pinion worse in another street car that I was trying to get to go faster than I probably should have. ..in any case, get the metal spur then let us know when you get up to 70, or 90 mph ...I'd love to see a CR'r beat an X0-1 !