I'm going to try this with Antenociti's and Relic Knights jetbikes.
Mongoose/Warlod are due to release four different sets of sci-fi bikers from the Judge Dredd setting (human, robot, zombie, ape) at some point in the medium term. They havent specified whether the bikes will be wheeled or anti-grav designs, although I suspect a mix of the two as thats what fits with the comic background. Obviously anti anti-grav types would be very suited to this.
Does the system work well enough both ways?
If possible then thats the way to go. If you have managed to pull off a rule set that makes racing in 28mm scale fun for its own sake, as in the meat of the system makes pure racing fun and competitive on its own then I really want to try it. Even so, all future sports tend to involve violence of some kind, so I would want the option to include that. But race mechanics that work are the most appealing (and most important) aspects to me at least.