Anti-Gravity Cycling

16/03/2014

Why does a moving bicycle stay upright? It seems a simple question but, as yet, nobody has been able to answer it exactly.

Scientists are getting closer but mystery still surrounds the precise way geometry, mass, gravity, velocity and gyroscopic forces combine to keep an articulated two-wheeler coasting along, even when there’s no rider.

Now one expert of bike stability, Professor Andy Ruina of Cornell University in Ithaca, New York, has been discussing a curious finding that adds a little more to our knowledge. Last year he presented it to a quiet meeting in Japan. This month he repeated it in the US. If you weren’t at either, here’s the gist.

First, his students built a tricycle, with one wheel at the front and three at the back.Bricycle static

Like most tricycles, the front wheel steers. Unlike most tricycles, there is an adjustable suspension spring for the rear set of wheels.

It’s not a suspension spring to absorb vibration. Instead, it can be adjusted to allow the tricycle’s rear wheels to lean into the corner, in the same way that the rear wheel of a bicycle leans in.

Pushing the bricycleWhen the suspension spring is given complete flexibility, the rear wheels tilt as the rider leans into the corner, exactly like a bicycle.

When the suspension is locked to rigid, the rear wheels are locked upright and the tricycle corners exactly like a tricycle.

That’s why Ruina has nicknamed this hybrid machine as a “bricycle” (not to be confused with the energetic Bricycles cycling pressure group in Brighton UK).

The weirdest thing happens, though, when the suspension is adjusted somewhere in between being being totally flexible and being locked rigid, at a critical point where it counterbalances the forces created for steering.

Leaning in anti-gravity

Suspension adjusted to eliminate the effect of gravity

At this setting, the suspension eliminates the effects of gravity.

It becomes an anti-gravity bricycle.

When the bricyclist tries to corner, by turning the front wheel and/or leaning towards the centre of the curve, the bricycle does not respond. It will not change direction. It just keeps on going straight on.

So, by switching off gravity, it’s impossible to alter course.

What does this clever experiment reveal?

Well, now we know that, as cyclists, without gravity we would be fated to riding forever in one direction. If we wanted to change course we’d have to stop, dismount, pick up our bicycle, turn it and start off again. Our bicycle would be as manoeuverable as a train that’s gone off the rails.

We may curse gravity when we’re riding uphill but, from now on, we should give gravity due praise every time we steer.

*I first stumbled across an abstract of Professor Ruina’s paper and tweeted it in January 2014, later that month he kindly engaged in a Skype conversation. Since then, he and his team have posted an explanatory video of the bricycle in action, with a full explanation of the physics at work. It’s well worth watching – several times!

"Shall we just cycle home?"

“Shall we just cycle home?”

Better out than in?

27/01/2014

Is it more effective to train outdoors than in?

In 2003 a woman with Parkinson’s Disease was the stoker on the back of tandem. To keep the pace being set by the male captain, she had to pedal much faster than was easy for her during the ride across Iowa. The happy result was that the symptoms of her degenerative disease were lessened significantly.

Since then, repeated intense exercise has been considered a good way to mitigate the debilitating symptoms of Parkinson’s Disease.

One result is that patients have been encouraged to work out on stationary bikes in gyms. As many cyclists know, this experience just doesn’t compare to riding the open road. It lacks the movement, fresh air and engagement with the real world that is afforded by a real spin.

Now research has shown that intensive cycling hard out on the road could benefit a person with early Parkinson’s Disease more than the same level of exercise on a gym bike.

Why is this?

“If person’s living with Parkinson’s were to be free to ride safely on a recliner bike or tandem bike, the external cues of other people on the bike trail and wildlife may do more for the person and their disease than riding on a stationary bike at home,” says Megan Joanna Avilla, in her Masters thesis, Acute effect of intense exercise on rhythmic gait in persons living with early Parkinson’s Disease.

She may be right. The experience of changing scenery, moving air, seeing people and sensing the environment might enhance the physiological effects of exercise.

If Megan Joanna Avilla’s thesis is correct, does it mean that all outdoor training for any cyclist is more effective than exactly the same exertion on rollers indoors? Do our bodies get fitter by riding through the open air than within four walls?

The implication for all cyclists, including those without Parkinson’s Disease, is that working out could be better than working in.

How much better? Has this been tested? If not, I volunteer (weather permitting).

training ride

Better out?

gym bike

Than in?

The Lessons of 2013

28/12/2013

Every week I scan the abstracts of about 25 new papers published in peer reviewed journals and by universities. Sometimes I have access to complete papers.

They are all relevant to cycling and I try to stick to the one that have some basis in, or relevance to, science. Considering I read only those written in English, ones that cross my radar and ones that I have any hope of understanding, clearly there’s a lot out there that I miss. Nevertheless, the pickings are rich and diverse.

While I tweet nearly everything I find (@cyclingscience1), here’s a summary of  a little of what I’ve learned this year from those thousands of diligent researchers who continue to add to our understanding of cycling.

I don’t necessarily agree with any of them.

• Yoga stresses the heart and respiratory system less than cycling
• The weaves of skinsuit materials affect your aerodynamics
• Bike reviews criticising comfort are largely untrustworthy
• Regenerative braking for e-bikes is going to blossom
• Cycling in London is either more dangerous or the safety models were wrong
• The Mayor of London is more worried about commerce than road safety
• Mountain bikers suffer the worst injuries in the first third of an endurance race
• French riders in the Tour de France live longer than mere French mortals
• Traffic calming and separate cycle paths make cycling safer in Netherlands
• Medics worldwide believe that bicycle helmets are fantastic
• The health benefits to US society of cycling outweigh the costs
• Caffeine definitely helps if you drink it, but not as a mouth rinse
• Cars don’t pass helmeted cyclists any closer than they pass bare-headed riders
• Steer by wire is on its way for e-bikes
• Support for, and research into, safety in numbers is growing
• Male cyclists have bigger thighs than triathletes
• The secrets of bicycle stability and steering remain enigmatic
• The best time to ride along Oxford Street in London is 10:07 on 25th DecemberOxford St cycling 25 Dec

To stay ahead of the bunch in 2014, buy a copy of Cycling Science and follow the tweets @cyclingscience1

Strava users help sports science – unwittingly

20/11/2013

Do you use Strava? If so, you may have contributed unwittingly to pioneering research that could help all cyclists.

Three Italian researchers accessed the data of almost 30,000 Strava-using cyclists. (Put simply, Strava is the social fitness app that tracks your ride and creates a leaderboard for all rides on the same route) The users were anonymous to the researchers so it could be anyone’s data – including your’s.

SocialBlog_In-Situ-1024x592Then the researchers mined this mountain of data. They wanted to see what kind of exercise leads to better performances.

Sports scientists, doctors, physiologists and others have been doing the same kind of research for decades. They’ve come up with a lot of credible theories – but they’ve been based on the results from a few dozen professional or, occasionally, a few hundred experienced participants.

Those old studies look tiny compared to the cohort used by Paolo Cintia, Luca Pappalardo and Dino Pedreschi of the Dept. of Informatics at the University of Pisa, Italy. Thanks to the Strava data, they had an enormous sample size of 29,284 cyclists to study. The vast majority of them would have been amateur (that’s you and me) and their fitness levels would have ranged from the near-elite to the pathetic (me).

In the old days the quantity of data would’ve been too much information to handle easily but, with every second of those riders’ activities in stored in digital form, the researchers were able to drill down relatively quickly.

Fortunately for all sports scientists and coaches, the findings from the huge sample corroborate what’s suspected already from the old, small studies. Exercise on its own doesn’t make you perform better; it’s down to training.

“Athletes that better improve their performance follow precise training patterns usually referred as overcompensation theory, with alternation of stress peaks and rest periods,” say Cintia, Pappalardo and Pedreschi.

“To the best of our knowledge, our study is the first corroboration on large scale of this theory, mainly confirming that “engine matters”, but tuning is fundamental,” they say.

Sadly the potential for data from Strava and other social fitness platforms to help scientists get new insights is now restricted. Paul Mach, an engineer at Strava and creator of Raceshape, implied by tweet that the researchers had only acquired the data because they had “hammered the v1/v2 API before it got shutdown. We blocked an Italian univ[ersity] IP a while back. Probably them.”

Screen shot 2013-11-20 at 15.55.01

This approach by Strava gives the company more control over who can access the anonymised data of its users. “Data acquiring has been a fundamental part of our work,” the Italian researchers say, “We did it through Strava’s API (version 2.0)*. Unfortunately, Strava changed his [sic] API policies in June 2013, so it is not possible to download data anymore.

“At that time, we asked Strava and they were still developing the new version of API. Now it seems that such new version is finally available but you need to request the access to Strava developers.”

Neveindexrtheless, expect more results soon from the Strava data that Cintia, Pappalardo and Pedreschi harvested before the tap was turned off. “Currently we are investigating other fascinating aspects emerging from Strava data, we hope to get new results for helping cyclists in their training life. Specially because we are cyclists, too,” they say.

And if Strava relents and let’s scientists get fresh data, it’s likely to be just one source of information that could benefit all of us, including the most pathetic riders (me) in unexpected ways. “We are sure that the increasing diffusion of training devices (powermeters, heart rate monitor etc) and social fitness applications will give us the possibility of a deep and new study of training science,” say Cintia, Pappalardo and Pedreschi.

Their research paper is available here and they were scheduled to present it in December 2013 at a workshop of the IEEE International Conference on Data Mining in Dallas, Texas

+++++++++++++

*Update at 16:56 GMT 20/11/13: From Paolo Cintia – “The data acquisiton was done after a request to Strava developer, explicitly highlighting the scientific and anonymous use. Furtherrmore the access to the API was public.”

Update at 09:00 GMT 5/3/14: From the researchers: “We are currently working on some improvements and extension of the cyclists’ study. Our purpose is to create a model able to detect if a person trains in the right way or not. In the meanwhile, we opened a blog where we tell in a divulgative way our scientific works. You can find a post about the cyclists’ study here

Ouch! How to hurt good on a mountain bike

03/09/2013

MTB injuries

Falling over themselves

05/08/2013

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!

31/07/2013

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

29/05/2013

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

30/04/2013

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

06/04/2013
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!


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