yeah, it's calibrated. i just don't have any top end speed (or the power to get up there) or the really high end speed endurance just yet. i have decently strong legs and great endurance from years of running but cycling is taking some getting used to. i also am 5' 6", and also very flexible, so i can get down pretty low and cut a very small swath in the air. so its not really that hard to get moving for me. the difference between myself and guys in the TdF is that i was on near-flat roads in the midwest, and those dudes are cranking up MOUNTAINS. it's not really a viable comparison.