@Bumblebee The width of the rear tire is telling me those sport bikes are at least 600s and I would say probably 1000s. A narrow tire should produce some advantages in cornering and the sumibaks have some very narrow tires. The sprockets look pretty big too. With the proper gearing it might not take a lot of horsepower to make a bike that small accelerate up to lower speeds as well as a bigger bike. They don't need to go over 70 mph on that track. The sport bikes aren't getting close to their top speed. If they could, I think they would have stood a much better chance of winning. The sumibaks look like they were made for that exact kind of track. They're probably riding right at the limit of power, weight and maneuverability for that track. The sport bikes can't use their speed and they have an obvious disadvantage in handling.