His plan for the summer is to randomly load the carbon bike with a 4 kg weight. This article first appeared in the British Medical Journal of December 9th, 2010, and is reprinted by kind permission.
Cities imply commuting, and the best commute is by bicycle. Can you cut your commuting time with an expensive, low-weight bike, or will a heavy bone-shaker do just as well? Jeremy Groves tested the difference.