How fast could you cycle in a vacuum?

Asked by: Carol James, London

When you ride a bike normally, the wind resistance increases with the cube of your speed. At 32km/h, the power needed to overcome the drag accounts for more than 75 per cent of the total cycling effort, and this rises to over 80 per cent at 40km/h.

Recumbent bikes, which have much lower profiles to reduce their wind resistance, can already reach speeds of over 80km/h.

If you removed air drag completely, the only friction would be from the tyres and the bearings. Provided you had a high enough gear ratio to allow your legs to pedal at an efficient pace, you could probably reach well over 150km/h.

An easy way to simulate this would be to try pedalling on a stationary bike, but there are no published records for this sport.

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