All you everyday cyclists who think hitting 40 mph on a downhill is fast, take note: British cyclist Tom Donhou reached 80 miles per hour recently on a fixie. Not just any fixie, though. Donhou designed and built this speedster himself, fitting it with a giant 104-tooth chainring, low center of gravity and reduced wind resistance.
Donhou conducted his speed experiment on an airport runway by riding behind a car, which reduced drag by displacing the air in front of him—similar to the "drafting" that professional cyclists do during road races.
In stationary trials Donhou had gotten the bike up to 100 mph.
Although the speed is certainly impressive, it’s less than half of the record. Dutch cyclist Fred Rompelberg set the record in 1995 when he reached approximately 167 mph on Utah’s Bonneville Salt Flats by riding in the slipstream of a dragster car.
In both cases the speed was only possible because of air displacement by the preceding vehicle. However, there's another way to hit racetrack speeds on a bike: In 2000, French cyclist Eric Barone hit 138 mph riding downhill on snow.
Watch Donhou's preparation and speed trial here: