We still don’t really know how bicycles work

Forget mysterious dark matter and the inexplicable accelerating expansion of the universe; the bicycle represents a far more embarrassing hole in the accomplishments of physics.

Let’s be honest, a bit of the pleasure at Chris Froome’s victory in the Tour de France is down to this being our second victory in a row and to the thought that the French haven’t won it since 1985. What must be worse for them, though, is that when it comes to the science of team cycling, even the Belgians are in front.
 
At the University of Mons, researchers are developing something called the Anaconda. It’s never going to be much of a speed machine because it is, in effect, a chain of monocycles with handlebars. These units are connected, by means of hinges that allow them to snake along, to a normal two-wheeled bike at the front. Every rider in the chain can be going in a slightly different direction, which means it takes an enormous amount of control and collaboration to move the thing forward. According to Olivier Verlinden, chief engineer on the project, the main qualification for riders is to be unafraid of falling off.
 
It’s fun, apparently. The idea is to unleash it as a beach-resort bike, the kind of thing that stag and hen parties will use to terrorise seaside towns across the world. But it is also scientifically interesting. Why? Because we still don’t really know how bicycles work.
 
It is rare that most people appreciate the bicycle, but it is quite an extraordinary machine. Push a riderless bike, letting it roll freely at high enough speeds, and it can withstand pushes from the side – it will wobble a little, but quickly recover. In the conventional analysis, that is because the gyroscopic force of the front wheel, its mass and the spontaneous turn of the handlebars all act together to keep the bicycle rolling forwards. This has something to do with the gyroscopic effect, the force that keeps a spinning top upright. You can feel this by removing a wheel from your pushbike and spinning it while you hold the axle spindles. If you try to change the orientation of the wheel, you’ll feel it push back against you.
 
The first mathematical analysis of bicycles suggested that this is also what keeps a moving bike on its wheels. But although the equations were written down in 1910, physicists always had nagging doubts about whether this was the whole story.
 
The most definitive analysis came exactly a century later. It involved an experimental bicycle that had all its gyroscopic effects cancelled out by a system of counter-rotating wheels. The effort of building such a strange contraption was worth it: the resulting paper was published the prestigious journal Science.
 
The publication plunged bicycle dynamics back into chaos. It turns out that taking into account the angles of the headset and the forks, the distribution of weight and the handlebar turn, the gyroscopic effects are not enough to keep a bike upright after all. What does? We simply don’t know. Forget mysterious dark matter and the inexplicable accelerating expansion of the universe; the bicycle represents a far more embarrassing hole in the accomplishments of physics.
 
And it may not be solved any time soon; very few researchers are working full-time on bicycle dynamics and there’s very little money in it. Once we’ve discovered exactly how these contraptions work, it might be possible to come up with bold new designs of bicycle – perhaps even better than the Anaconda. But nobody is desperate for that to happen; not even the French.
 
Maybe that’s OK. In an age where we have worked out the history of the cosmos and the secret of life, it’s rather nice that the humble bicycle keeps our feet on the ground. 
 
Cyclists during the Tour de France. Photo: Getty

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 29 July 2013 issue of the New Statesman, Summer Double Issue

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Jeremy Corbyn's Labour conference speech shows how he's grown

The leader's confident address will have impressed even his fiercest foes. 

It is not just Jeremy Corbyn’s mandate that has been improved by his re-election. The Labour leader’s conference speech was, by some distance, the best he has delivered. He spoke with far greater confidence, clarity and energy than previously. From its self-deprecating opening onwards ("Virgin Trains assure me there are 800 empty seats") we saw a leader improved in almost every respect. 

Even Corbyn’s firecest foes will have found less to take issue with than they may have anticipated. He avoided picking a fight on Trident (unlike last year), delivered his most forceful condemnation of anti-Semitism (“an evil”) and, with the exception of the Iraq war, avoided attacks on New Labour’s record. The video which preceded his arrival, and highlighted achievements from the Blair-Brown years, was another olive branch. But deselection, which Corbyn again refused to denounce, will remain a running sore (MPs alleged that Hillsborough campaigner Sheila Coleman, who introduced Corbyn, is seeking to deselect Louise Ellman and backed the rival TUSC last May).

Corbyn is frequently charged with lacking policies. But his lengthy address contained several new ones: the removal of the cap on council borrowing (allowing an extra 60,000 houses to be built), a ban on arms sales to abusive regimes and an arts pupil premium in every primary school.

On policy, Corbyn frequently resembles Ed Miliband in his more radical moments, unrestrained by Ed Balls and other shadow cabinet members. He promised £500bn of infrastructure investment (spread over a decade with £150bn from the private sector), “a real living wage”, the renationalisation of the railways, rent controls and a ban on zero-hours contracts.

Labour’s greatest divisions are not over policy but rules, strategy and culture. Corbyn’s opponents will charge him with doing far too little to appeal to the unconverted - Conservative voters most of all. But he spoke with greater conviction than before of preparing for a general election (acknowledging that Labour faced an arithmetical “mountain”) and successfully delivered the attack lines he has often shunned.

“Even Theresa May gets it, that people want change,” he said. “That’s why she stood on the steps of Downing Street and talked about the inequalities and burning injustices in today’s Britain. She promised a country: ‘that works not for a privileged few but for every one of us’. But even if she manages to talk the talk, she can’t walk the walk. This isn’t a new government, it’s David Cameron’s government repackaged with progressive slogans but with a new harsh right-wing edge, taking the country backwards and dithering before the historic challenges of Brexit.”

After a second landslide victory, Corbyn is, for now, unassailable. Many MPs, having voted no confidence in him, will never serve on the frontbench. But an increasing number, recognising Corbyn’s immovability, speak once again of seeking to “make it work”. For all the ructions of this summer, Corbyn’s speech will have helped to persuade them that they can.

George Eaton is political editor of the New Statesman.