Im sorry you are wrong.Im speaking from experience. enough said. Im sure CDA could school me on his 450 anywhere.See your obviously right EVERYTIME I can see your point with the 250f thing but it's just like lifting weights. Let's say your curling a 40lb. Dumbbell every week for 6 weeks at the end of six weeks your going to be curling that thing like a champion. When you have a 450 you don't just go all out until you know your capabilities and you will adapt to the heavier bike as you go, giving you more muscle and letting you control the bike with more ease