Science has proven that it takes 12 pounds of weight reduction to gain 1 mph on a bike. obviously a 120 pound rider on a 15 pound carbon bike is going to have some advantage over another rider who weighs the same but is riding a 20 pound bike. Having said that it still has more to do with the motor than the bike. You could put me on a UCI tour legal bike and while I may go faster than I normally do on my vintage steel bikes, I am still not going to keep up with a pack of fit and fast riders on vintage steel racers hell bound for glory .