He used to go to Three Sisters and another at north pickering, both cart tracks, where the 510 was great but Caldwell and Oulton park needed the extra. Chances are the extra weight might have shown up more in the tight twisties and braking but we're all greedy at times.
When the Supermoto's raced at Cadwell they cut the upper section off the track as they were all bouncing off the rev limiters.