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

Show Hide image

A group of men united only by sport was once my idea of hell. What changed?

It struck me, during the course of our team’s annual pre-season dinner, how much I like my team-mates. 

To the cricket team’s annual pre-season dinner. Although I’ve been playing for them for ten years or so, I’ve never been to one of these. This is because when I say “I’ve been playing for them for etc…” you’re probably not getting the right picture. What I mean is: I have played ten matches for them, and last year not at all, with a highest score of 22, and an average of 10.17. If you think that’s unimpressive, it’s a lot better than when I was a schoolboy, and I am just 26th placed out of 50 people who have played ten or more matches for them. Last year I was 25th, I see. Well, I’m going to have to do something about that.

The idea is that if I go to the dinner this time, it will inspire me to get in shape and play a game or two this season. I almost invariably enjoy it when I do, especially the time I was in a record-breaking tenth-wicket partnership of 72 while batting with a broken hand. (Well, finger. But a finger’s a part of the hand, isn’t it? Even the little finger.) I suppose there are times when I don’t enjoy it so much, such as when it’s raining hard enough for the cows in neighbouring fields to sit under a tree, but not hard enough to send us back to the pavilion or, better still, the pub, and the opposition are clouting us all over the ground despite the weather, and if we’d batted first – we never bat first, in my (limited) experience – the other lot would have polished us off about an hour ago, and we could now all be cosily inside the pavilion or, as I said earlier, even better, the pub. Then again, the team is called the Rain Men, so what did I expect?

So signing up for games involves considering a number of factors: some kind of mystic calculation about what the weather will be like, an assessment of how far away the ground is (we’re a nomadic team, so we don’t have one of our own), and how fit I think I’m going to be on the day. That’s the troublesome part. There is, of course, the melancholy of coming back, aching and knackered, at what is usually well after nine in the evening on a Sunday, lugging a cricket bag, like someone who has not been able to let go of his childhood and is out after his bedtime.

The fitness, as I said, is problematic. I got slightly out of puff going for a pee between the second and third paragraphs of this column, so I think there is going to be a lot of tedious spadework in store for me. My dumb-bells are in East Finchley, which I don’t go to, although as my cricket stuff is there too I suppose I’m going to have to bite that bullet sooner or later. If I eschew the dumb-bells then there will always be the floor, gravity, and push-ups. There will always be stairs, somewhere, I can run up and down, while I have the use of my legs. While there is an earth I can walk upon, I can walk upon it. The upper body strength, so I can pick up a cricket bat without falling over, is the thing to aim for, but right now the main goal is to be able to get out of bed and go to the loo without getting winded.

Anyway, the dinner. I decided that I’d walk to the restaurant. This was largely because the restaurant is about 200 yards from where I am holed up at the moment. There is, literally, only one restaurant closer to me. I walked a bit more than 200 yards because I had to swing by Sainsbury’s to pick up a couple of bottles of wine (the McGuigan’s Reserve Cab Sauv at £6.50 a bot, special offer, being the sedative of choice these days), as the restaurant is unlicensed. We met at the pub first, of course.

It struck me, during the course of the evening, how much I like my team-mates. I am by no means the oldest, so many of them are rich in wisdom and experience. (Amazingly, the team won more games last season than it has in its history, but that might have been because I hadn’t played for them.) Two of the people I am particularly fond of couldn’t make it, but at least I got to have A Long Rant About Life In General with Marcus Berkmann, author of two extremely amusing books about the team (Rain Men and Zimmer Men), as well as the greatest book about Star Trek ever written (Set Phasers to Stun).

Imagine: a long table sat at by a group of about 15 men, united only by a sport. It would once have been my idea of hell. So why is it not now? Is it because I actually like these guys? They’re not the typical idea of a cricket club gang, I have to say that. And we do, admittedly, talk about cricket a fair amount. But still. (I even liked I—, who gave up smoking and then had a rush of blood to the head last year and sent a round-robin email to the team saying how much he hated A—, one of our most lovable players. I— couldn’t make it to the dinner, largely on the grounds of not having been invited.) Or am I that lonely? 

Nicholas Lezard is a literary critic for the Guardian and also writes for the Independent. He writes the Down and Out in London column for the New Statesman.

This article first appeared in the 12 April 2018 issue of the New Statesman, Syria’s world war