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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Rarely has it mattered so little if Manchester United won; rarely has it been so special they did

Team's Europa League victory offers chance for sorely needed celebration of a city's spirit.

Carlo Ancelotti, the Bayern Munich manager, memorably once said that football is “the most important of the least important things”, but he was only partly right. While it is absolutely the case that a bunch of people chasing around a field is insignificant, a bunch of people chasing around a field is not really what football is about.

At a football match can you set aside the strictures that govern real life and freely scream, shout and cuddle strangers. Football tracks life with such unfailing omnipresence, garnishing the mundane with regular doses of drama and suspense; football is amazing, and even when it isn’t there’s always the possibility that it’s about to be.

Football bestows primal paroxysms of intense, transcendent ecstasy, shared both with people who mean everything and people who mean nothing. Football carves out time for people it's important to see and delivers people it becomes important to see. Football is a structure with folklore, mythology, language and symbols; being part of football is being part of something big, special, and eternal. Football is the best thing in the world when things go well, and still the best thing in the world when they don’t. There is nothing remotely like it. Nothing.

Football is about community and identity, friends and family; football is about expression and abandon, laughter and song; football is about love and pride. Football is about all the beauty in the world.

And the world is a beautiful place, even though it doesn’t always seem that way – now especially. But in the horror of terror we’ve seen amazing kindness, uplifting unity and awesome dignity which is the absolute point of everything.

In Stockholm last night, 50,000 or so people gathered for a football match, trying to find a way of celebrating all of these things. Around town before the game the atmosphere was not as boisterous as usual, but in the ground the old conviction gradually returned. The PA played Bob Marley’s Three Little Birds, an Ajax staple with lyrics not entirely appropriate: there is plenty about which to worry, and for some every little thing is never going to be alright.

But somehow the sentiment felt right and the Mancunian contingent joined in with gusto, following it up with “We’ll never die,” – a song of defiance born from the ashes of the Munich air disaster and generally aired at the end of games, often when defeat is imminent. Last night it was needed from the outset, though this time its final line – “we’ll keep the red flag flying high, coz Man United will never die" – was not about a football team but a city, a spirit, and a way of life. 

Over the course of the night, every burst of song and even the minute's silence chorused with that theme: “Manchester, Manchester, Manchester”; “Manchester la la la”; “Oh Manchester is wonderful”. Sparse and simple words, layered and complex meanings.

The match itself was a curious affair. Rarely has it mattered so little whether or not United won; rarely has it been so special that they did. Manchester United do not represent or appeal to everyone in Manchester but they epitomise a similar brilliance to Manchester, brilliance which they take to the world. Brilliance like youthfulness, toughness, swagger and zest; brilliance which has been to the fore these last three days, despite it all.

Last night they drew upon their most prosaic aspects, outfighting and outrunning a willing but callow opponent to win the only trophy to have eluded them. They did not make things better, but they did bring happiness and positivity at a time when happiness and positivity needed to be brought; football is not “the most important of the least important things,” it is the least important of the most important things.

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