Archive for the ‘Uncategorized’ Category

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


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.

The lure of the future


There’s been a flurry of news about genuinely new technologies for bikes, mostly involving digital electronics. These stories are seductive because they fulfil our desire for an exciting, better future. I know this all too well – I earned a living from writing such stuff for more than a decade.

One downer is that most of them are chimeras. They never materialise. In Britain it’s known as the Tomorrow’s World effect, after a TV programme that, each week, highlighted innovations but which were never seen again.

Of course, that’s a little unfair. While the novel devices and gadgets don’t themselves become commercial products, some of the underlying technologies are picked up and find their way into successful, popular designs.

So that’s my excuse for showcasing a few of the innovations for cyclists that have floated across the internet recently. They may disappear, they may become mainstream or the ideas embedded within them may surface in a completely different manifestation. Whatever – they’re fun.

A head case from MIT

Wired has featured a helmet that, allegedly, can detect brainwaves. It’s a student project at MIT and it has been suggested that it could be used to detect the intentions of cyclists and trigger the operation of digitally controllable electronic components. So it could, with a single thought, illuminate a left-turn light.

Meanwhile, Cambridge Consultants have turned a smartphone into a virtual gearlever and so do away with human thought altogether, according to my old editor Paul Marks at New Scientist. With its internal accelerometer, a prototype app and a Bluetooth connection to the electronic gear mech, the mobile phone makes the chain shift between cogs automatically and maintains a steady cadence for the rider.

Stop me and buy one

If the Bluetooth connectivity tech from Cambridge Consultants is allied with MIT’s helmet they could be harnessed by Saarland University’s digital braking system. Then all a rider would need to do would be to think about slowing and, hey presto, the brakes would be applied, the tyres would never skid because the wheels would have a digital anti-lock function and the gearing would change down automatically and make it easier to start pedalling.

Full of holes

Battery-powered enhancements are not for everyone so how about a puncture-proof tyre? Britek Tire and Rubber came up with an air-less car tyre almost a decade ago but have not yet succeeded in going mainstream with it. Now they hope that mountain bikers might adopt it. I’d love to hear from anyone who has ridden these tyres.

Full of good in tensions

Finally, something that genuinely deserves to be supported by the cycle industry – an independent lab for assessing the friction of all bicycle components. Friction pales in comparison to drag in terms of wasting a cyclist’s energy but, with aerodynamics becoming reasonably well understood, this new facility should become very busy as riders want to shave even more seconds off their competition times.

That’s the future. Maybe. Waddyou reckon?

25 days to go


It’s been a long time coming but it’s almost there. Cycling Science by Max Glaskin

In 25 days my book on Cycling Science is due to be published. It occupied me for almost a year and, at times, it was not a comfortable journey. Finding science relevant to cycling that can also be illustrated with detailed infographics was a new challenge for someone used to dealing only with words, not illustrations. For instance, how can inertia, a fundamental influence on cycling, be illustrated clearly and easily? If you have an answer, please do send it via the Comment option below.

Nevertheless, by scouring the academic journals it was possible to pull together several hundred pieces of research that deserved to be explained clearly in words and graphics so that cyclists can understand better how they work with their bikes. Some of the science and data may be familiar to the keenest but the book covers such a wide spectrum, from environment and physiology to aerodynamics and technology that it’s likely more than 90% will be new information to most readers.

I finished work on the book in July 2012, after which my editors (seven at the last count) spent some time preparing it for printing. So I haven’t yet seen it and wait expectantly and nervously for the first advance copy. Although there is a pile of early page layouts stacked at the end of my desk, I know that whole spreads may have changed entirely and many, many tiny details tweaked.

This blog is an open continuation of the book. There are items of science research relevant to cycling that are published almost daily somewhere in the world. I’ve been tweeting them (@cyclingscience1) as often as possible so that they become known to an audience outside the universities and research labs. Every so often I add a short item to my Facebook page (Cycling Science).

This blog, thouygh, is meant to broaden the conversation, to receive feedback about the book, to hear directly from scientists and to disseminate and discuss the latest findings. If it works, it should be a lively read. If it doesn’t, well, I’ll just get on my bike and I’d suggest that you do, too.

Max Glaskin