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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Tom Watson rouses Labour's conference as he comes out fighting

The party's deputy leader exhilarated delegates with his paean to the Blair and Brown years. 

Tom Watson is down but not out. After Jeremy Corbyn's second landslide victory, and weeks of threats against his position, Labour's deputy leader could have played it safe. Instead, he came out fighting. 

With Corbyn seated directly behind him, he declared: "I don't know why we've been focusing on what was wrong with the Blair and Brown governments for the last six years. But trashing our record is not the way to enhance our brand. We won't win elections like that! And we need to win elections!" As Watson won a standing ovation from the hall and the platform, the Labour leader remained motionless. When a heckler interjected, Watson riposted: "Jeremy, I don't think she got the unity memo." Labour delegates, many of whom hail from the pre-Corbyn era, lapped it up.

Though he warned against another challenge to the leader ("we can't afford to keep doing this"), he offered a starkly different account of the party's past and its future. He reaffirmed Labour's commitment to Nato ("a socialist construct"), with Corbyn left isolated as the platform applauded. The only reference to the leader came when Watson recalled his recent PMQs victory over grammar schools. There were dissenting voices (Watson was heckled as he praised Sadiq Khan for winning an election: "Just like Jeremy Corbyn!"). But one would never have guessed that this was the party which had just re-elected Corbyn. 

There was much more to Watson's speech than this: a fine comic riff on "Saturday's result" (Ed Balls on Strictly), a spirited attack on Theresa May's "ducking and diving; humming and hahing" and a cerebral account of the automation revolution. But it was his paean to Labour history that roused the conference as no other speaker has. 

The party's deputy channelled the spirit of both Hugh Gaitskell ("fight, and fight, and fight again to save the party we love") and his mentor Gordon Brown (emulating his trademark rollcall of New Labour achivements). With his voice cracking, Watson recalled when "from the sunny uplands of increasing prosperity social democratic government started to feel normal to the people of Britain". For Labour, a party that has never been further from power in recent decades, that truly was another age. But for a brief moment, Watson's tubthumper allowed Corbyn's vanquished opponents to relive it. 

George Eaton is political editor of the New Statesman.