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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What type of Brexit did we vote for? 150,000 Conservative members will decide

As Michael Gove launches his leadership bid, what Leave looks like will be decided by Conservative activists.

Why did 17 million people vote to the leave the European Union, and what did they want? That’s the question that will shape the direction of British politics and economics for the next half-century, perhaps longer.

Vote Leave triumphed in part because they fought a campaign that combined ruthless precision about what the European Union would do – the illusory £350m a week that could be clawed back with a Brexit vote, the imagined 75 million Turks who would rock up to Britain in the days after a Remain vote – with calculated ambiguity about what exit would look like.

Now that ambiguity will be clarified – by just 150,000 people.

 That’s part of why the initial Brexit losses on the stock market have been clawed back – there is still some expectation that we may end up with a more diluted version of a Leave vote than the version offered by Vote Leave. Within the Treasury, the expectation is that the initial “Brexit shock” has been pushed back until the last quarter of the year, when the election of a new Conservative leader will give markets an idea of what to expect.  

Michael Gove, who kicked off his surprise bid today, is running as the “full-fat” version offered by Vote Leave: exit from not just the European Union but from the single market, a cash bounty for Britain’s public services, more investment in science and education. Make Britain great again!

Although my reading of the Conservative parliamentary party is that Gove’s chances of getting to the top two are receding, with Andrea Leadsom the likely beneficiary. She, too, will offer something close to the unadulterated version of exit that Gove is running on. That is the version that is making officials in Whitehall and the Bank of England most nervous, as they expect it means exit on World Trade Organisation terms, followed by lengthy and severe recession.

Elsewhere, both Stephen Crabb and Theresa May, who supported a Remain vote, have kicked off their campaigns with a promise that “Brexit means Brexit” in the words of May, while Crabb has conceded that, in his view, the Leave vote means that Britain will have to take more control of its borders as part of any exit deal. May has made retaining Britain’s single market access a priority, Crabb has not.

On the Labour side, John McDonnell has set out his red lines in a Brexit negotiation, and again remaining in the single market is a red line, alongside access to the European Investment Bank, and the maintenance of “social Europe”. But he, too, has stated that Brexit means the “end of free movement”.

My reading – and indeed the reading within McDonnell’s circle – is that it is the loyalists who are likely to emerge victorious in Labour’s power struggle, although it could yet be under a different leader. (Serious figures in that camp are thinking about whether Clive Lewis might be the solution to the party’s woes.) Even if they don’t, the rebels’ alternate is likely either to be drawn from the party’s Brownite tendency or to have that faction acting as its guarantors, making an end to free movement a near-certainty on the Labour side.

Why does that matter? Well, the emerging consensus on Whitehall is that, provided you were willing to sacrifice the bulk of Britain’s financial services to Frankfurt and Paris, there is a deal to be struck in which Britain remains subject to only three of the four freedoms – free movement of goods, services, capital and people – but retains access to the single market. 

That means that what Brexit actually looks like remains a matter of conjecture, a subject of considerable consternation for British officials. For staff at the Bank of England,  who have to make a judgement call in their August inflation report as to what the impact of an out vote will be. The Office of Budget Responsibility expects that it will be heavily led by the Bank. Britain's short-term economic future will be driven not by elected politicians but by polls of the Conservative membership. A tense few months await. 

Stephen Bush is special correspondent at the New Statesman. He usually writes about politics.