Cycling Science: 7 Fascinating Facts About Bikes




The Invisible Foe

Every cyclist knows the burn they feel from defying gravity to pedal uphill. But the ubiquitous factor fighting cyclists' performance is air. Dry air at sea-level pressure (about 14.7 psi) and at 70 F, has a density of about 0.075 lb/ft3. Good aerodynamics reduce how much a cyclist is impeded, but only so much.

That hasn't stopped some cyclists and scientists from trying to defeat drag. The velodrome at the 2012 London Olympics was engineered to raise track temperatures to 82 F and make the air thinner, boosting the likelihood of world record times. Outdoors, however, the only strategy to defeat air is to go race at higher elevations where it's less dense. That's one reason Jennie Longo chose Mexico City for her world hour record bids in 1989 and 1996. At 7342 feet above sea level, the density of dry air at 60 F falls to below 0.062 lb/ft3, which gave Longo an extra 0.93 mph compared to recent rides she'd made at sea level.