I know I shouldn't compare myself to others, but I do. I wanna go faster, I just can't seem to do over 10-11 mph avg. speed. I see all these folks talking about how they have avg of 15+ and I just want to do the same. I switched up my tires to 28's, I have been working on spinning instead of mashing, and I even started using clipless shoes. When it gets really hilly, I am only hitting a 8mph avg. Anyone have any tips?