There arent any 'slow' karts, the 100cc karts im talking about can run on FE Club or AS Cadet (AS Cadet is VERY similar to buckmore park), but gear them up and they can run on any track, it happens in real life. The gearbox karts dont need their own tracks, they will run perfectly on the car tracks we already have. Gearbox karts in real life race on Silverstone, Brands Hatch and Cadwell Park for example.