Video: The physics of better bikes

Mathematical models can be used to design a better recumbent bike (Image: David L. Moore/Alamy)

Forget finding a theory of everything – we can’t even explain how bicycles work

IT IS almost dark at the Technical University of Delft in the Netherlands, but that hasn’t stopped the world’s foremost authorities on the bicycle from careering around a car park on two wheels. It’s clear from the carnage that most are theorists. They might work with the maths behind bicycling on a daily basis, but it looks like some of them don’t ride bikes much.

Or perhaps that’s being a little harsh. Some of these bikes are ridiculous. They are meant to be improvements on the standard bicycle, but it is clear that a near-perfect design evolved decades ago. The 1970s bike made of flexible plastic might have won design awards, but it is terrifyingly shaky. Then there is the bike with two wheels on its rear axle which is hair-raisingly unstable when cornering. And the electric bikes, though fun, have a tendency to zoom away as soon as the rider starts to pedal, leaving them grabbing for the brakes.

Proving a particular problem are the low-slung recumbent bikes, in which the rider sits close to the floor. Spectacular crashes of these machines result in a mess of corduroy wrapped around metal. Trousers are extricated slowly and painfully. Then – with all the stubbornness that comes with years of wrestling seemingly intractable mathematical problems – the rider gets back in the saddle.

“Spectacular crashes of these low-slung bicycles result in a mess of corduroy wrapped around metal”

Such …