Falling over themselves


ImageThere’s a fair amount of cycling science research that seems, on the face of it, quite silly. And there’s been a little clutch of such projects published in the last month. Here’s one.

You know when you’ve fallen off your bike, don’t you? Several of your senses tell you irrefutably that you are no longer pedaling upright but are, instead, upside down with your head in a termite nest and your feet in a giraffe’s mouth.

Nevertheless, five Korean engineers, who may be among the small minority of Koreans who have yet to buy the Korean edition of my book, think the human body needs help in identifying when cycling’s gone wrong.

They’ve put a tilt switch and an accelerometer inside their helmets. Whenever they fall off their bikes, the sensors emit a signal. Uncertain as to the significance of these signals, the engineers perfected algorthms to fuse and analyse the data.

Now they are utterly confident that this marvellous technology tells them they have fallen over.  “The algorithm of the third method we developed achieved 100% accuracy in fall direction,” they crow.

Well done, chaps, at last there’s technology to rival the top-tube gadget of the 1980s that told you when you were cycling up hill.

Listen up!


traffic bicycleSshhh! Cycling’s way down the list of noise polluters. A well-maintained bike on a smooth surface can be near-silent (assuming the rider isn’t wearing chain mail, playing a bugle or both). The peacefulness is one of its pleasures.

So that makes a bicycle a relatively good platform for collecting other sounds on the move. What you do with those noises is up to you and different scientists are doing surprising things.

There’s a team in Austria that’s been eavesdropping on a rider as she pedals around the town of Graz. She knew about it. Before she started she phoned the lab and kept the call connected. The researchers were able to hear all the sounds around her wherever she cycled.

Then they analysed the audible clues and, like sound detectives with their ears to the ground, they succeeded in working out her route just from the noises they heard through her phone. It’s an impressive result.

It’s not clear from this experiment who had the most fun but it does show that even if you doubt the existance of Big Brother (he does exist), it seems that he doesn’t need to watch you to find out where you are. All he has to do is listen and he’s got you located.

The research paper will download when you click here.

Elsewhere, three unfamous (as yet) Belgians have been cycling round cities capturing the traffic noise as they ride. At the same time they’ve been sampling the air, not just through their own mouths and noses but also through chemical sensors.

They made 200 trips and then calculated that there is a relationship between traffic noise and the level of carbon particles that pollute the air. This shouldn’t be very surprising because it stands to reason that the more traffic there is, the noiser it is and the greater the quantity of pollutants they are pumping into the atmosphere.

Here’s the clever thing about the research. Lots of people want to know how dirty the air is in our city streets at different times of day and in different weather conditions. The general aim is to keep the air cleaner somehow or other and thus improve everybody’s health. The problem, though, is that air quality monitoring equipment isn’t cheap.

By showing that noise levels are a reliable indicator of air pollution levels, the Belgian team says that audio recordings captured by street-level microphones can reveal the truth just as effectvely as air quality sensors. And microphones are much, much cheaper.

How ironic that the toxic emissions from motor vehicles will be more easily monitored because of an experiment by cyclists.

The abstract of the research can be seen here.

Read on, online, dear reader


Cycling Science by Max GlaskinWith your shelves now groaning under the burden of all the editions of Cycling Science (in at least five languages if you count US English and UK English as different flavors), then you will be pushed for space to store any more books. So here’s the first round-up of websites that you might find useful to further your interest in science related to cycling.

For aerodynamic drag force formulas (formulae?) there’s Rainer Pivit’s explanation – try not be put off by the symbols. They only want to be your friend.

The dynamics of the peloton aren’t as clear as they might appear in those sweeping shots from the helicopter during the Grand Tours. In fact, it’s a dynamic of transient mathematical beauty and it is being explained in all it’s glory by Hugh Trenchard.

Hugh Trenchard's peloton modelIf you want to cut to the chase, Hugh has built a great model online that you can actually play with – choosing rider numbers, speed, drafting distance etc. It mimics the real thing convincingly and is just as entrancing. (Personally I like the way the whole page looks. Somehow it reminds me of the early online scientific animations of the mid-’90s, although it is far more sophisticated and driven by powerful algorithms.)

What else? Ah yes, how about a short diversion into physiology. How on earth do your bulging leg muscles work? Don’t ask me, ask the experts. There is everything you need to know and more at the ExRx site for exercise professionals.

Me and my muscles before I put on my Lycra

Me and my muscles before I put on my Lycra

And just how much extraordinary power are your muscles producing? Well, you could buy some power cranks or one of the many other devices you can fit to a bike or you could simply enter some data into the site created by Walter Zorn and watch it calculate the answer in a jiffy. Walter Zorn died in 2009 but his family and friends maintain it in his memory.

That’s it for now. More soon.

How to Acquire a Third Testicle


The public has spoken so don’t blame me. And it’s nothing to do with Flann O’Brien.

A few days ago I listed three topics I might cover in this post. One was on electromechanical systems for bicycle control. Another was about the dynamics of a peloton. However, both were outvoted by the third option – the medical phenomenon known, loosely, as the cyclist’s third testicle.

Of course, the phenomenon can only manifest itself among half of the world’s population (at most). Nevertheless, the other half, women, may have a vicarious interest and there’s no doubt that some men reading this are driven by similar prurience.

But how many men reading this actually possess the hat-trick of spheres? The chances are higher if you’re a full time, elite professional cyclist than if you’re an occasional leisure rider. It seems that the longer you’re in the saddle, the more likely you’ll develop the titular extra ball.

A cyclist's third testicleTo be absolutely honest, it’s not actually a testicle. Not having seen one in the flesh myself, and with no great urge so to do, I’d wager that it doesn’t even look much like a testicle. Yet medics, members of a profession to which we entrust our lives, have branded it a “testicle” so that’s how it shall be known.

In reality, it’s a perineal nodular induration. Before you go scrimmaging in your scrotum to see if that’s what you’ve got, you should know that it is a soft mass. It doesn’t hurt. It doesn’t transmit pain unless maltreated – and who’d want to maltreat such an innocent growth anyway?

It sits just beneath the scrotum. Sometimes it develops as two nodules (as nobody has yet applied the name “fourth testicle” I’ll claim that great privilege right now) but when it is undivided it’s called the third testicle.

The tenth anniversary of its recognition by doctors falls next month, when three (of course) researchers from Belgium published their seminal paper “Perineal Nodular Induration: The Third Testicle of the Cyclist: An Under-Recognized Pseudotumour”.

If you want a third testicle, get a road bike with a very stiff frame, pump the tyres so they are very hard, fit an extremely unforgiving saddle and cycle along a bumpy road for several years. The fatty or collageneous tissue of your perineum will eventually degenerate and form the pseudocyst that you are seeking.

It’s benign, even when it’s the size of an orange, like the one in the photo. Yet if, after you’ve gone to all the trouble of developing it, you find it’s not living up to your expectations, it can be removed. By a surgeon. With a sharp knife. And a steady hand.

*A full year after the above was posted, medics working in the UK have published a paper describing a similar case, in a 57 year old “avid” cyclist, in which they use a term I’d not seen before, “Biker’s Nodule”. You can read the abstract of “An avid cyclist presenting with a ‘third testicle'” here. I hope, for all cyclists’ sake, this isn’t the start of a trend…

Wake up and smell the coffee

The strongest is at the top, the weakest at the bottom. Cycle fastest with an espresso - hence its name.

The strongest is at the top, the weakest at the bottom. Cycle fastest with an espresso – hence its name.

AG2RThanks to a timely tweet by Asker Jeukendrup (@Jeukendrup), I got to read about new research that shows coffee can improve performance as effectively as caffeine on its own.

The paper, one of whose authors is Asker, can be read here.

What caught my eye in subsequent tweets was that different coffees contain different caffeine levels.

This is somethng I learned nine years ago during one of my more bizarre commissions.

I had to drive the length of England to collect 25 coffee samples, mostly from motorway service stations. It wasn’t the most pleasant way to spend two days.

The Centre for Mass Spectrometry at the University of Sussex generously agreed to measure the samples. It’s the lab where Professor Sir Harry Kroto first identified the form of carbon now known as buckyballs and for which he received a Nobel Prize.

The results were more stimulating than a treble espresso/Red Bull cocktail.

They showed that the strongest coffee contained more than 25 times as much caffeine as the weakest.

So, if you’re gong to drink coffee to ride faster for longer, don’t drink a Nescafé Latté from the Sutton Scotney service station on the A34.

Better to start your ride in Cheshire, at the Sandbach servces on the M6,with an Espresso double from Costa Coffee. Vrooooom!

Mind the gap – how close do cars come?


How much room does a driver give a cyclist when overtaking? What do you do as a cyclist when a car is passing you? How straight is the line you ride as vehicles pass you by? A group of scientists in Taiwan built a special bike to answer these questions and more.

Bicycle instrumented for rider/driver behaviour

All the on-board kit

It was instrumented to record lateral distance from the passing motorists, wheel angle and speed control. That’s a lot of special kit to add to a bicycle on city streets. It includes an ultrasonic sensor, camera, a variable resistor in the headset and a solid state compass, gyroscope and accelerometer. OK, it costs less than a CF disc wheel but it’s a lot of value to expose to potentially hazardous situations.

Well, as with the vast majority of urban rides, nothing went wrong and the data were analysed. Thirty-four riders were overtaken a total of 1,380 times. The equipment revealed that

• motorbikes passed more closely to the bicycle than cars and trucks did.

• cyclists couldn’t keep such a straight line when buses overtook

• vehicles passing slowly led to more cautious but less stable riding

• a solid white line, like for a bike lane, increases the distance between passing vehicles and bicycles
• motorists pass closer to men than women.
This last point confirms the 2007 findings of Dr Ian Walker of Bath University and some subsequent US research.
However, what’s not clear from the latest research is how much the beaviour of the riders and the drivers was influenced by the test itself. The riders would’ve at least been aware of the equipment of the bike and so may have ridden differently from normal.
Likewise the motorists could’ve seen the oddly-equipped bicycle and so changed from their normal steering pattern.
Nevertheless, I like this kind of research because it attempts to quantify experiences familiar to every cyclist and so it helps by converting anecdotes into evidence that may be used to improve road safety.


The use of a quasi-naturalistic riding method to investigate bicyclists’ behaviors when motorists pass, published in  Accident Analysis & Prevention, available online 29 March 2013, by Kai-Hsiang Chuang, Chun-Chia Hsu, Ching-Huei Lai, Ji-Liang Doon and Ming-Chang Jeng

Read on, dear reader…


Cycling Science by Max GlaskinNow that the UK edition of Cycling Science is only a few weeks away from publication (2nd May by Frances Lincoln) I can get round to suggesting other books you might enjoy that are relevant to the science of cycling.

And I might just sneak this blog entry under the wire before the end of March, if I’m quick.

The original book covering the subject is 117 years old. Bicycles and tricycles:an elementary treatise on their design and construction, with examples and tables” was written by Archibald Sharp and published in 1896. If you want to know about geometry and a whole lot more, you can read it online or download all 12.6MB of it for free.

Bicycling Science

If you are really interested in the engineering and physics of cycling, the standard textbook is Bicycling Science by David Gordon Wilson, with contributions by Jim Papadopoulos. The third edition was published in 2004 by the MIT Press. In places it’s quite academic but it contains a massive amount of technical information.

High Performance Cycling

The irrepressible Asker Jeukendrup edited a collection of essays, largely focusing on aspects of physiology, from many contributors in High-Performance Cycling, published by Human Kinetics in 2002. While a lot of new stuff has been discovered since the book was published, it’s got some great peices that are of practical help to competitive cyclists.

High Tech Cycling

The second edition of High-Tech Cycling, edited by Edmund Burke, was published by Human Kinetics in 2003. The essays from 13 different authors look mainly at the relationship between the cyclist and their machine, although there are also chapters relating to physiology and nutrition. A little dated now but I like it.

richards_bicycle_book_covFinally, how can I fail the mention the book that got me started so many years ago? I don’t have a copy any more so I’m going by my fallible memory when writing that it contained very little science. Yet its chapters on riding and maintenance encouraged me to ride further, more often and more enjoyably. What more can one want from a cycling book? It’s Richard’s Bicycle Book, a paperback published in the UK in the 1970s. If you buy it, let me know what you think.

And if you want to recommend other books relevant to cyclng and science, do send me an email or comment below.

Two new technologies – Number 2

I prefer the one on the left but spend too long, too often, looking at the one on the right

I prefer the one on the left but spend too long, too often, looking at the one on the right

OK, so you were less than overwhelmed by my shock revelations that Sturmey Archer might just perhaps possibly may be about to produce a 16 speed hub gear for bicycles. Jeez, some people are never satisfied.

How about this then? This will turn your world upside down. If it doesn’t then don’t blame me because the problem lies deep in your psyche and you’re not the kind of person I want visiting my blog anyway.

The big technology revelation today is, wait for it, something that means you won’t have to hang around at traffic signals waiting for them to go from red to green while you’re standing patiently astride your bicycle for ages and ages. There, quite a shocker, I think you’ll agree. What follows is the explanation of the problem and the latest solution.

Too many traffic signals have induction loops ahead of them, cut into the road. They detect the metal in cars, lorries, buses and even motorbikes with ease, and pass the data to the control box. When the system inside the control box decides the traffic’s been queuing long enough, it gives them the green light.

But induction loops are utter rubbish at detecting cyclists and bicycles. The problem is that most cyclists and many parts of bicycles are not made out of metal so the induction loops don’t spot us when we arrive. Subsequently, the control box doesn’t know we’re there and, unless another vehicle pulls up, it will never change the signal to green and we’ll wait. And wait. And wait until our patience snaps and we ride through a red light, get spotted by a saintly motorist who then writes to their local newspaper/councillors/police to condemn every single cyclist in the world as a monster the likes of which hasn’t been seen riding on our planet since Attila the Hun.

Of course, we all know that it’s all our fault, we cyclists should stop whinging and be grateful that we’re allowed on the roads anyway.  The obvious solution is that we should all start wearing chain mail and suits of armour containing sufficient metal to be seen by the induction loops.

However, some of us think that there should be a better way for traffic signals to know that cyclists are waiting for a green light. Fortunately, people at Sensys Networks agree. They make their money from traffic technology and they’ve seen how roads agencies might like to buy products that will assist the growing number of cyclists.

Sensys MicroRadar

Seen this on the road? Let me know – and ask your local traffic engineers to install them wherever there’s traffic signals

They’ve invented something branded as MicroRadar. It’s a little box that can be sunk into the road surface. It has a battery so it doesn’t need to be connected to any power supply. It communicates wirelessly with the control box. And, as its name suggests, it uses radar – to detect cyclists. Yippeee!

The diligent among you, by which I mean all of the most beautiful and clever readers of this blog, will already have searched for Sensys and MicroRadar and discovered that, quite unusually, this blog is two years behind the curve. I acknowledge that Sensys released the product in 2011. So why am I devoting valuable pixels to it now?

Because I have discovered that the first such unit in the UK is being trialled. Somewhere out there, on a road on the British mainland, cyclists are being detected by radar and getting a green light on the traffic signals when they might otherwise have to wait for an annoyingly long time.

Talking of being annoying, I’m going to have to be annoyingly reticent about its exact location. I know in which urban conurbation it is sited but I would be breaching confidentiality if I was any more specific. I wasn’t told not to reveal it but the information came to me without any knowledge I’d be writing about it here. See? I do have some morals. Not many, for sure, but I really don’t want to end up as aggregate under some new motorway widening scheme so I shan’t push my luck any further.

If you can be as patient as a cyclist waiting for a green light, the location will probably be released on 16th April 2013 and, if I remember, I’ll post it on the blog. Until then, if you want to know exactly where it is, you’ll have to study the road surface every time you approach some traffic signals.

Of course, if you do spot it and happen to post the info on the web before 16th April, please let me know so that I can republish it without fear of being accused of breaking my informant’s trust.

In the meantime, in case my informant is unhappy with this blog entry and for self-protection reasons only, I shall now put on my chain mail and suit of armour.

Two new technologies – Number 1


Technology is science made useful – well, that’s my excuse for posting this item, and the next, about two inventions that could impact cycling. Also, it’s hard to lose the habits I acquired as a budding news hound and I’d like to think I’m the first to bring them to a wider audience.

The first technology is that most mysterious of components – the hub gear. I guess it’s only enigmatic because it’s one of the few bits of a bike that you can’t see working. Those with oil under their nails and a lot of free time have probably taken them apart to understand exactly how the cogs and wheels interact. Me? I have the nails of a dilletante and the free time of a Mayfly.

Ben Cooper, though, knows more about these things and has kindly shared some of his knowledge with my via his tweets. He’s given me some background which helps to substantiate my suspicions that a new, humungous 16 speed hub gear is on its way.

I first got curious when I came across an academic paper (as you do when you’re me) published in Applied Mechanics and Materials. It covers a broad range of topics, including the updraft power of a solar tower, packaging and hydrology – but you, as a regular subscriber, would know that anyway.

Then, in its online edition of 25 January 2013, my eye was drawn as if by sorcery to a paper by Yi Chang Wu and Pei Wun Ren. I’d never come across their work before and forgive me if it’s not new to you, the regular subscriber.

It seems that Wu and Ren have been hard at work analysing hub gears. Not just any old hub gears, but enormous ones with 16 speeds. I’d never heard of such daring. Their paper, “Mechanical Efficiency Analysis of a 16-Speed Bicycle Transmission Hub” does just what it says on the tin. You, the regular subscriber, have probably digested it already but to me it was a revelation.

It showed that people are actually thinking of cramming 16 planetary gears inside the hub of a bicycle wheel. Heavens to Betsy. That could be so helpful for commuters in hilly cities and touring tandemists. Why has nobody every thought of it before?

Actually, it turns out they have. The very same Yi Chang Wu, then working with Shi Liang Lin, had written about it some two years previously. How I’d overlooked their paper “Conceptual Design of a 16-Speed Bicycle Drive Hub”, published in the March 2011 edition of Applied Mechanics and Materials, I’ll never know. I must’ve blinked.

And this is where Twitter came to my aid, in the generous form of helicopter and bicycle builder Ben Cooper. He gave me some history – saying that there had been speculation that Sturmey Archer had been working on just such a design but it was shelved when the company was bought by Sun Race in 2000 and all assets and production were moved to Taiwan.

That, for me, was enough to fantasise wildly. Sun Race is designing and making Sturmey Archer hub gears in Taiwan. Sturmey Archer’s assets may well have included designs for a 16 speed hub gear. Two papers co-authored by Yi Chang Wu are published about research into a 16 speed hub gear. Where is Yi Chang Wu based? Taiwan.

Putting it all together, in the excitable way of someone who has never looked inside a hub gear and whose own brain cogs are beginning to jam, the future of the world seems clear. Any day now Sturmey Archer will be launching a 16 speed hub gear – if they haven’t done so already by the time you read this. Remember where you read it first.


If you got carried away reading this as over-enthusiastically as I did writing it, you may like to check back in a few days to read the forthcoming post about the second new technology I’ve found that should soon benefit cycling and cyclists.

More contenders for 2012 Cycling Science awards


Here’s a couple of new nominations for the 2012 Cycling Science award. If you would like to suggest others, please use the reply form at the bottom of this page.

Out for the count

City planners need the right information to make the best decisions for encouraging cycling. Unfortunately the best information isn’t always available so they compromise and try to extract it from other sources.

For example, they should use accurate traffic counts when assesing the need for road design changes and the construction of better facilities for cycling, either cycle lanes or separated cycle paths.

The trouble is, they sometimes rely on those induction loops embedded in the asphalt and that are often there as part of the traffic signal system. They believe they detect every wheel that crosses them. They are so, so wrong.

While it’s common for the loops to ignore cyclists altogether, it seems from research at Ohio State University that they can’t always detect the lumps of metal that are cars and trucks.

Some of the induction loop counters were wrong by a massive 52%. Such inaccurate data must never be used in designing cycling facilities on or adjacent to the highway.

Head case

There are three things that careful researchers avoid:

1. Entering the febrile arena of discussion about bicycle helmets

2. Questioning head on accepted wisdom, such as that which evolves from Cochrane reviews

3. Taking the time to correct the mistakes made by others.

So three cheers to Rune Elvik at the Institute of Transport Economics in Norway and editor of Accident Analysis and Prevention.

He’s done all three in a dense little paper, which will infurate the pro-helmet lobby because one of its conclusions is that “no overall effect of bicycle helmets could be found when injuries to head, face or neck are considered as a whole.