The UCI hour rule change, a record resurgent?

After a quiet period of nearly a decade, the UCI’s ‘cycling hour record’ has been making news again over the past year. In February, the time trial powerhouse Fabian Cancellara announced that he would attempt the record in August — an amazing opportunity to see how a cyclist of the modern era stacks up against legends such as Eddie Merckx and Chris Boardman. Athletes were beginning to consider tackling the legendarily brutal challenge which Merckx described as the longest hour of his career.

Given this, it was strange to read in April that Cancellara was already postponing his plans following a rumour that the UCI was considering a change to the rules. Sure enough, in May an official announcement was made. The proposed rule change greatly affects the type of bike and hence the technology which is available to the athlete.

So what are these changes and what does it mean for the legendary hour?

The Hour

The UCI hour record is, in essence, a very simple one. It tests how far a cyclist can ride, around a track, in an hour. Despite this simplicity, the history of the event is spotted with complexity and controversy. Rapid technological advances in the ’80s and ’90s saw astonishing leaps in the distances being covered. During a technological arms race from 1993 to 1996 the record was pushed on by 4,800 m. It had taken 36 years prior to 1993 to achieve the same level of progress.

Worried that the event was becoming more about the bike than its rider, the UCI imposed stringent rule changes, banning the advances in frame design and rider position which occurred during that period. As an illustration of the severity of these changes, the ‘Lotus’ bike from 1992 offers a stark reminder — it appears astonishingly modern despite being over two decades old*.

The Bike of the future, from 1992

As a response to these changes, Chris Boardman (the holder of the record in 1996 at 56.4 km) made another attempt at the record in 2000, this time using a bike which was of a more ‘traditional’ design with circular tubing, drop handlebars and based on the bike legendary cyclist Eddie Merckx had used in his successful 1972 attempt (49.4 km). This was Boardman’s swansong, locking horns with ‘the cannibal‘ and attempting ‘the hour’ without any recent technological benefits — he beat Merckx’s effort by only 10 metres.

The UCI, clearly enamoured by Boardman’s idea adopted it as the official hour record, creating rules which would require any pretenders to use a bike roughly in-line which Merckx’s of 1972. These new rules** restricted the technology available to the cyclist, they had to use a traditional frame design with circular tubing (no smaller than 2.5 cm in diameter), drop handlebars, spoked wheels, and shallow section rims.

The rampant use of technology had been halted, the hour record was to be preserved in the era of steel tubes and riding caps.

Technology rules

The hour record is of particular interest to the Sports Engineer, I first became aware of its interesting history when giving lectures in schools and to the public. It was a perfect example of the relationship between sport and technology. On one hand it demonstrates the huge performance benefits which can be obtained, on the other, it illustrates how governing bodies react to technology’s threat. In this case the UCI thought that the rapid advances in frame design and rider position were detracting from the purity of the event itself. The record was being broken not necessarily due to a rider’s physical effort but due to the technological expertise they had access to. A level playing field, a concept universally aspired to in sport (especially ball sports), was not in effect — something had to change.

The UCI were making a clear statement by changing the rules and forcing a rider to use a bike similar to the one used by Eddie Merckx in 1972. They drew a line in the sand, the records made after 1972 were ‘technologically doped’. The distances achieved by those riders were down — in some part — to the technology available at the time and no longer valid.

This must have been influenced in some way by the significant status Eddie Merckx has in the cycling pantheon. His legendary status is such that it’s hard for the cycling community to believe anyone can beat him without some kind of nefarious assistance. However, I also think it’s because that after his record in 1972, athletes started to overtly embrace technology; the bikes and the positions of the riders visibly changed. Compare Francesco Moser’s 1984 bike to Merckx’s from 1972.

Technology in plain sight, compare Merckx’s 1972 bike on the left, with Francesco Moser’s on the right

However, wouldn’t Merckx wasn’t also embrace all the technology that he had available? This scanned article from 1991, describes his obsession with weight (ironically, the effect of weight is tiny compared to aerodynamic forces), and the considerable preparations taken to ensure the bike was optimised for the event. Following this argument, it is naive to assume that every athlete who has ever attempted the hour hasn’t taken every step to ensure they bested the distance of their predecessor. Chris Boardman, even with his self-imposed restrictions was able to adopt a number of technological ‘optimisations’ which may have given him an edge — notice the aerodynamic skinsuit in this picture of his attempt. There is ample speculative headroom to consider whether technology was the deciding factor in his attempt considering that he was in the twilight of his career and beat Merckx’s distance by only ten metres .

Recent rule changes

The UCI’s recent rule changes may seem puzzling when fully considered. They are scrapping the arbitrary technological limitations that have governed the record for 14 years. Any bicycle which is legal for any track-based time trial (i.e. the pursuit event) is now permissible in the hour record. This means carbon fibre, streamlined tubing and the stretched ‘time-trial’ riding position (to get an idea of the advantage these kind of technologies permit see our previous article). It also means that all the previously banned records are re-instated, but the current record still stands at 49.7 km (achieved in 2005 by Ondřej Sosenka). For someone unaware of the history of the event it now seems that Boardman beat his own record of 56.4 km in 1996 by riding 49.4 km in 2000.

For years, rules have restricted the technological advantages available to the rider. A relaxation of these rules almost guarantees that the next serious contender will break the current record and take their place in the history books. The level playing field which connected the efforts of riders today with those of Merckx in ’72 has been upset.

How does this work? How are the technological improvements available today any more worthy than those pioneered by Moser, Obree and Boardman in the ’80s and ’90s? I think this move represents an admission by the UCI that technology is intrinsic to progress in sport and without progress athletes and enthusiasts lose interest.

Riders have stayed away from ‘the hour’ because it required training in a completely different way, on completely different equipment and even then the chances of success are slim. By bringing the hour record into the modern era more athletes will be able to justify attempting the record while at the top of their game. Where athletes go, crowds of fans will follow, crucially, the rule change could breathe life into an event stifled by technological prohibition.

It’s great to be able to compare modern performances with those of heroes past but this only works if athletes continue to engage. I don’t think the crowds flocked to velodromes in the ’90s because they were looking to compare a performance with one made more than 20 years ago. I believe the attraction and passion came from a contemporary sense of competition. They went to see if team Obree could beat team Moser or team Boardman; every new victory coming from an extra modicum of effort, an insight or an innovation. Each performance was a combination of athletic prowess and technological innovation.

With rumours that Fabian Cancellara, Tony Martin and Bradley Wiggins may now be considering an attempt at the hour record, we could be returning to a time of great public interest  and great competition in this event. I hope the UCI can embrace technology and its positive effect on the sport.

Simon Choppin

P.S. I do have one question though (Devil’s advocate alert), with news that Cancellara was going to attempt the record anyway, why change the rules at all? I’d have loved to have seen how he stack up against Merckx!

*For a more detailed description of the history of the hour record please see Michael Hutchinson’s book ‘the hour‘.

**For the sake of simplicity, I’m ignoring the UCI’s ‘best human effort’  hour record in this article

Gravity Racer World Record: The Record Attempt

It was time to see if we could set a world record speed for a gravity racer. The weather was 21ºC in nearby Avignon and the wind on the 2 km road section was light. Feeling buoyant from the previous day’s 81.8 mph and having a number of further changes up our sleeves — we were optimistic.

The record

The weight of the racer before the attempt was 194.5 kg and we added 5.5 litres (5.5 kg) of water to reach the maximum 200 kg weight. This was distributed mainly to the rear of the gravity racer following Guy’s feedback on its driveability. Brake bias was adjusted and the tyres were pumped up to 84 psi. It is important to stress that all of these changes were made incrementally on each run to allow Guy to adjust to the changes in handling and for us to verify what each speed increase was attributed to. Eventually, the optimum set up was achieved and Guy drove the gravity racer into the Guinness World Record book with a speed of 85.6 mph!

The crash

The record had been broken and Guy was already looking to the next challenge; to see how fast the gravity racer could go. Thoughts of breaking 90mph were clearly on his mind. Our time on the mountain was also coming to an end so there was not the time to make further incremental changes. A number of further changes were made at once, including adding further weight. The braking and handling had significantly shifted and Guy commented that he probably should have come to a stop after the first bend but it was now or never and what was the worst that could happen…..

Interestingly Guy managed to tame the racer right up until the final straight when he lost control whilst braking and crashed in spectacular style. “That was the best crash of the year!” Guy claimed laughing as he climbed out completed unharmed. The team breathed a huge sigh of relief — the gravity racer’s safety design of steel tubular frame and 5 point safety harness had been tested to its limit, and passed.

Will we be repairing the racer?

No – although the frame appears intact it has now been put under significant stresses and we can no longer be confident in its structural integrity.

Could we have gone faster?

Yes of course! Our gravity racer was conceived, designed and built within 4 months; this in itself is a fantastic achievement. We had some great comments on the blog and thank you for the interest! We do not think our design is perfect and we look forward to seeing the challengers to our world record!

The UCI hour rule change, a record resurgent?

After a quiet period of nearly a decade, the UCI’s ‘cycling hour record’ has been making news again over the past year. In February, the time trial powerhouse Fabian Cancellara announced that he would attempt the record in August — an amazing opportunity to see how a cyclist of the modern era stacks up against legends such as Eddie Merckx and Chris Boardman. Athletes were beginning to consider tackling the legendarily brutal challenge which Merckx described as the longest hour of his career.

Given this, it was strange to read in April that Cancellara was already postponing his plans following a rumour that the UCI was considering a change to the rules. Sure enough, in May an official announcement was made. The proposed rule change greatly affects the type of bike and hence the technology which is available to the athlete.

So what are these changes and what does it mean for the legendary hour?

The Hour

The UCI hour record is, in essence, a very simple one. It tests how far a cyclist can ride, around a track, in an hour. Despite this simplicity, the history of the event is spotted with complexity and controversy. Rapid technological advances in the ’80s and ’90s saw astonishing leaps in the distances being covered. During a technological arms race from 1993 to 1996 the record was pushed on by 4,800 m. It had taken 36 years prior to 1993 to achieve the same level of progress.

Worried that the event was becoming more about the bike than its rider, the UCI imposed stringent rule changes, banning the advances in frame design and rider position which occurred during that period. As an illustration of the severity of these changes, the ‘Lotus’ bike from 1992 offers a stark reminder — it appears astonishingly modern despite being over two decades old*.

The Bike of the future, from 1992

As a response to these changes, Chris Boardman (the holder of the record in 1996 at 56.4 km) made another attempt at the record in 2000, this time using a bike which was of a more ‘traditional’ design with circular tubing, drop handlebars and based on the bike legendary cyclist Eddie Merckx had used in his successful 1972 attempt (49.4 km). This was Boardman’s swansong, locking horns with ‘the cannibal‘ and attempting ‘the hour’ without any recent technological benefits — he beat Merckx’s effort by only 10 metres.

The UCI, clearly enamoured by Boardman’s idea adopted it as the official hour record, creating rules which would require any pretenders to use a bike roughly in-line which Merckx’s of 1972. These new rules** restricted the technology available to the cyclist, they had to use a traditional frame design with circular tubing (no smaller than 2.5 cm in diameter), drop handlebars, spoked wheels, and shallow section rims.

The rampant use of technology had been halted, the hour record was to be preserved in the era of steel tubes and riding caps.

Technology rules

The hour record is of particular interest to the Sports Engineer, I first became aware of its interesting history when giving lectures in schools and to the public. It was a perfect example of the relationship between sport and technology. On one hand it demonstrates the huge performance benefits which can be obtained, on the other, it illustrates how governing bodies react to technology’s threat. In this case the UCI thought that the rapid advances in frame design and rider position were detracting from the purity of the event itself. The record was being broken not necessarily due to a rider’s physical effort but due to the technological expertise they had access to. A level playing field, a concept universally aspired to in sport (especially ball sports), was not in effect — something had to change.

The UCI were making a clear statement by changing the rules and forcing a rider to use a bike similar to the one used by Eddie Merckx in 1972. They drew a line in the sand, the records made after 1972 were ‘technologically doped’. The distances achieved by those riders were down — in some part — to the technology available at the time and no longer valid.

This must have been influenced in some way by the significant status Eddie Merckx has in the cycling pantheon. His legendary status is such that it’s hard for the cycling community to believe anyone can beat him without some kind of nefarious assistance. However, I also think it’s because that after his record in 1972, athletes started to overtly embrace technology; the bikes and the positions of the riders visibly changed. Compare Francesco Moser’s 1984 bike to Merckx’s from 1972.

Technology in plain sight, compare Merckx’s 1972 bike on the left, with Francesco Moser’s on the right

However, wouldn’t Merckx wasn’t also embrace all the technology that he had available? This scanned article from 1991, describes his obsession with weight (ironically, the effect of weight is tiny compared to aerodynamic forces), and the considerable preparations taken to ensure the bike was optimised for the event. Following this argument, it is naive to assume that every athlete who has ever attempted the hour hasn’t taken every step to ensure they bested the distance of their predecessor. Chris Boardman, even with his self-imposed restrictions was able to adopt a number of technological ‘optimisations’ which may have given him an edge — notice the aerodynamic skinsuit in this picture of his attempt. There is ample speculative headroom to consider whether technology was the deciding factor in his attempt considering that he was in the twilight of his career and beat Merckx’s distance by only ten metres .

Recent rule changes

The UCI’s recent rule changes may seem puzzling when fully considered. They are scrapping the arbitrary technological limitations that have governed the record for 14 years. Any bicycle which is legal for any track-based time trial (i.e. the pursuit event) is now permissible in the hour record. This means carbon fibre, streamlined tubing and the stretched ‘time-trial’ riding position (to get an idea of the advantage these kind of technologies permit see our previous article). It also means that all the previously banned records are re-instated, but the current record still stands at 49.7 km (achieved in 2005 by Ondřej Sosenka). For someone unaware of the history of the event it now seems that Boardman beat his own record of 56.4 km in 1996 by riding 49.4 km in 2000.

For years, rules have restricted the technological advantages available to the rider. A relaxation of these rules almost guarantees that the next serious contender will break the current record and take their place in the history books. The level playing field which connected the efforts of riders today with those of Merckx in ’72 has been upset.

How does this work? How are the technological improvements available today any more worthy than those pioneered by Moser, Obree and Boardman in the ’80s and ’90s? I think this move represents an admission by the UCI that technology is intrinsic to progress in sport and without progress athletes and enthusiasts lose interest.

Riders have stayed away from ‘the hour’ because it required training in a completely different way, on completely different equipment and even then the chances of success are slim. By bringing the hour record into the modern era more athletes will be able to justify attempting the record while at the top of their game. Where athletes go, crowds of fans will follow, crucially, the rule change could breathe life into an event stifled by technological prohibition.

It’s great to be able to compare modern performances with those of heroes past but this only works if athletes continue to engage. I don’t think the crowds flocked to velodromes in the ’90s because they were looking to compare a performance with one made more than 20 years ago. I believe the attraction and passion came from a contemporary sense of competition. They went to see if team Obree could beat team Moser or team Boardman; every new victory coming from an extra modicum of effort, an insight or an innovation. Each performance was a combination of athletic prowess and technological innovation.

With rumours that Fabian Cancellara, Tony Martin and Bradley Wiggins may now be considering an attempt at the hour record, we could be returning to a time of great public interest  and great competition in this event. I hope the UCI can embrace technology and its positive effect on the sport.

Simon Choppin

P.S. I do have one question though (Devil’s advocate alert), with news that Cancellara was going to attempt the record anyway, why change the rules at all? I’d have loved to have seen how he stack up against Merckx!

*For a more detailed description of the history of the hour record please see Michael Hutchinson’s book ‘the hour‘.

**For the sake of simplicity, I’m ignoring the UCI’s ‘best human effort’  hour record in this article

Journal Special issue: Association Football

Every time the FIFA world cup comes around, there is a flurry of research into football. This may be aerodynamics, shoe traction or impact mechanics. To capture the research conducted surrounding the 2014 World Cup in Brazil, journal Sports Engineering is planning a special issue on association football.

If you have some research which you think would be at home in the journal please see the flyer or contact the associate editors Simon Choppin (s.choppin@shu.ac.uk) or Tom Allen (t.allen@shu.ac.uk).

WHAT EVER HAPPENED TO THE WOODEN ICE HOCKEY STICK?

Technology has had a profound impact on the sporting world and it is the reason for the sudden disappearance of the wooden ice hockey stick.

Over the last decade, there have been large advances in the technology of the ice hockey stick. Material, manufacturing and structural advances in composites have allowed manufacturers to create an ice hockey stick that combines the properties of wood and aluminium to improve performance. However, as with anything, there is still room for improvement.

Figure 1: The Mi’kmaq people of Nova Scotia, Canada making ice hockey sticks in the late 19th century.

The Mi’kmaq people of Nova Scotia, Canada are said to be the inventors of the ice hockey stick and may have been playing ice hockey as early as the 18th century. They carved their sticks from ironwood and recently, one of their ice hockey sticks from the 1850s was appraised  and sold for US$2.2 million. As ironwood supplies diminished in the 1920s, ash became the preferred material. In the 1940s, a more flexible and durable laminated ice hockey stick was created in which layers of wood were glued together. In the 1960s, companies added an additional synthetic compound as a coating to further increase the durability of the stick and players began curving the blade to improve shot performance.  Aluminium sticks became very popular in the late 1980s and early 1990s, thus challenging the traditional wooden stick.

Video – Discovery Channel Compares the Wooden Hockey Stick with the Composite Hockey Stick

The advent of composite technologies has revolutionized many sports, ice hockey was no exception — many of the old designs have been swept away in a wave of carbon, fiberglass and kevlar. Using a combination of materials results in performance improvements because of the stick’s decreased mass and increased durability. Although these sticks are more expensive and have a limited effect on the performance of non-professional ice hockey players, most players have switched over to them, regardless of age or skill level. Currently, less than 10 NHL players (<2%) use a wooden ice hockey stick, and the numbers in minor ice hockey are even lower. One key issue is that of durability and an up-and-coming company, COLT Hockey, appears to have found a solution: nano-materials. COLT Hockey says that their sticks are 50% stronger than elite composites and, given their recently successful kickstarter campaign, their innovation could be the next big advance in ice hockey stick design.

Video – The COLT: Engineering A Better Ice Hockey Stick

Despite these advances, there will always be an opportunity for improvement, no matter how developed a sport and its equipment may be. How long will it be until we are asking, “what ever happened to the composite ice hockey stick?”

References:

Cutherbertson, B. (2005). The Starr Manufacturing Company: Skate Exporter to the World. Journal of the Royal Nova Scotia Historical Society, 8, 50-65.

Ernst, M.E. (2014). Composite Technology and the Hockey Stick Revolution. Illumin, 15(1).

Laliberte, D.J. (2009). Biomechanics of ice hockey slap shots: which stick is best? The Sport Journal 12.1. Academic OneFile. Web: 30 January 2014.

N.A. “COMPANIES DEFEND NEW-AGE HOCKEY STICKS; BREAKAGE SEEN DURING NHL PLAYOFFS GIVES FALSE IMPRESSION, EASTON VICE-PRESIDENT SAYS.” Record, The (Kitchener/Cambridge/Waterloo, ON) n.d.: Newspaper Source Plus. Web: 30 January 2014.

About the Author:

Andrew Chapman is a Canadian student who is currently working towards completing an MSc in Sports Engineering at Sheffield Hallam University in the United Kingdom. He previously completed a BSc in Kinesiology at Laurentian University in Canada. He is an avid sports enthusiast who has an interest in sports technology and innovation. Andrew puts high importance towards continued education and research, with the mindset that there is always more to learn and something that can be improved. He has a background in baseball and tennis research, in which he focused on performance improvements and injury reduction. He enjoys playing all sports and is always eager to join in on a game with friends and/or volunteer his time towards helping others on and off the sports field.

Image competition!

Share your images showcasing the best in sports science, engineering, and technology in the ISEA 2013/14 Image Competition.

Do you have an image that showcases the outstanding research and consultancy being conducted within sports engineering? If so the International Sports Engineering Association want to hear from you!

The ISEA is running a competition to uncover captivating and exciting imagery that showcases the best in sports science, engineering and technology.  The competition is open to all involved in sports engineering and science, and has categories for both traditional photographic images, and computer generated imagery. Each image submission must be accompanied by a short 150 word abstract describing the image and the science behind it.

A prize of £250 will be awarded to the image judged best in show. Additionally winners of each image category will receive a prize of £100. Ten best in show runners up will each receive £25. The competition closing date is 1^st April 2014, entries will be judged by a panel from academia and industry with winners being announced 30^th April 2014. Winning entries will be exhibited at The Engineering of Sport 10 Conference, the worlds largest gathering of experts working in the field of Sports Engineering, and also appear on this blog.

For more information and to enter the competition visit www.sportsengineering.org/imagecompetition/

Football and skill: why you’re not as individual as you think you are

As much as I hate football (for explanation – I’m a Blackburn Rovers fan; enough said) I’m enjoying my holiday read.  It’s The Numbers Game by Chris Anderson and David Sally and is subtitled “Why everything you know about football is wrong”.  It’s not actually the best thing to relax to as I keep jumping up and exclaiming its use/ful/less facts to my family across the sun lounger and then has me scrabbling for the calculator on my smartphone.

Hopefully, this blog will excise this particularly active demon and finally allow me to relax and read my novel, which is what I’d intended until I picked up The Numbers Game.  I was struck by the comments made by Mssrs Anderson and Sally about the balance in football between skill and luck, which can be calculated in lots of different ways to be around 50/50.

The basics: passing the ball

Their first figure contains data from English 1^st Division between 1953 and 1967 and shows the frequency of the number of passes in a move when an interception was made (Figure 1).  The most common was zero at 39.4%  (they must’ve been watching Rovers), i.e. they didn’t even manage one successful pass almost 2/5 of the time before interception by the opposition.  Players managed a single pass before interception on the second 27.5% of the time and two successful passes before interception 16.5% of the time.  Unsurprisingly, a sequence of 6 passes only occurred 1% of the time.

The data points towards the fact that football spends a lot of the time at equilibrium with attack and defence cancelling each other out so that goals become a rarity.  The numbers were updated by Anderson and Sally using 2011-12 data for the Premier League (source: StatDNA) which showed that the distribution had shifted so that there were fewer sequences of two or less passes and more sequences of four or more passes (Figure 2).  Perhaps this is not so surprising: the modern game is a lot about possession football and one might expect more trains of long sequences of passes compared to the players of the mid-20^th Century.

An 1880s Model of football

What is surprising, though, is that the distribution is remarkably similar to a finding made by Simon Newcombe in the 1880s and named after Frank Benford for his work in the 1930s.  Benford’s Law or the First Digit law predicts how many times the digits 1 to 9 would appear in a list of numbers.  In this case, the law works if we change the thing we are counting from “number of passes” to “the number of the pass when an interception occurs” so that we are looking at the number of consecutive passes made.  This makes the first pass a digit 1 rather than 0 (which possibly makes more sense anyway).

Figures 3 and 4 show that Benford’s Law predicts the number of passes of the 2011-12 Premier League pretty accurately.  The message to coaches it gives is that they should expect around 30% of first passes to be intercepted, with 70% being successful.  Around half of moves with one or two passes will be intercepted and the other half will get through.  The % of interceptions increases as the number of passes increases so that there is only a 1 in 10 chance that any move with up to 7 passes will be successful.

Why Benford’s Law?

This is where I admit that I don’t know why Benford’s Law should hold for the number of passes in football. It seems that, despite the best efforts of the players on the pitch, they more or less follow a theory of numbers which also applies to a wide range of real life situations (one of which is cricket).  It seems that the Law describes human behaviour very well and soccer players are not as individual as they might like to think.

—

References:

Reep, C & Benjamin, B (1968) Skill and Chance in Association Football, Journal of the Royal Statistical Society, 131, 581-585.

Cycling’s a drag, but it doesn’t have to be

July 11, 2013 by wiredchop

After a regrettably lengthy hiatus from the blog, this article was inspired by the excellent aerodynamics segments of the ITV’s tour de France coverage (in collaboration with Southampton University).

Cycling aerodynamics in the 1980’s

A few years ago my colleague Dr Richard Lukes wrote a review paper titled “The understanding and development of cycling aerodynamics” published in the Sports Engineering journal. The paper handily tabulates a number of different cycling positions and equipment choices — along with the associated aerodynamic effect.

Cycling aerodynamics

The subject has been discussed at length in books and online, but I would like to briefly add my own thoughts. A cyclist maintaining a steady speed is subject to a number of resistive forces: the rolling resistance of the tyres, the friction in the chain and bearings and the aerodynamic resistance to motion — the force required to ‘push’ the air aside. Of all these forces aerodynamic drag is usually the greatest (at slow speeds and on steep hills this may not be the case) — at race speeds aerodynamics drag has been measured to account for 96% of total resistance [1]. The factors determining aerodynamic drag are complex, resistance to motion can be expressed as an equation we’ve used many times before:

The resistive force is equal to half of the product of: air density, airflow velocity (squared), the area in contact with the airflow and a factor which is referred to as the ‘drag coefficient’ — C_D. C_D is usually measured directly (in wind tunnel tests) and is determined by the shape of the rider (a ‘streamlined’ rider has a lower C_D than one sat up in the airflow) and the nature of the airflow (whether it is laminar or turbulent).

Professional bike riders try to minimise aerodynamic equations by affecting on of the terms of the above equation. Streamlined tubes and helmets lower C_D, textured fabrics create turbulent airflow (lowering resistance in the same way as the dimples on a golf ball) and changing riding position lowers area and C_D. However, the greatest advantage comes from lowering the velocity of the airflow — due to the fact this term is squared. Since a professional rider doesn’t have the option to slow down, they tend to put something in the way of the air, e.g. another rider or the back of a team car. This video shows an extreme example of this.

Why lower drag?

Usually one of two reasons, to save energy, or to go faster. At a constant speed, we can think of the equation above as a balance; the force produced by the rider is equalled by the aerodynamic forces acting upon them (for the sake of simplicity I’m disregarding rolling resistance etc.). During a long day in the saddle a rider can maintain race speeds at much lower efforts by staying amongst the peloton. When staying in the bunch isn’t an option – during an individual time trial or solo breakaway – a rider wants to translate the power they produce into as much speed as possible. Lowering aerodynamic drag (either by reducing C_D and/or A) allows velocity to increase without increasing the power requirement from the rider. This is useful if we assume that for any race the power (or force) a rider can maintain for any period of time is limited – equipment or riding positions which reduce aerodynamic drag are essential to create a competitive edge. A great example of this is Graeme Obree, while undoubtedly a great cyclist, his greatest advantages came from the innovations he created in bike design and body position which reduced his aerodynamic drag – they allowed him to go faster. In fact, Grappe et al. [2] measured the aerodynamic drag of the ‘Obree position’ and found it to be 20% lower than the standard ‘dropped’ position.

Grame Obree in his record breaking, aerodynamic position.

The equipment

So what equipment is worth using? The table below shows a selection of items taken from Dr Lukes’ paper, listing the aerodynamic advantage which can be obtained.

NB: Due to the complexity of drag and the dependence on rider size, velocity etc. All of these values should be taken as representative rather than absolute. Dr Lukes lists a number of sources in each case, I’ve taken the most recent values.

Innovation	Aerodynamic force reduction	Notes
Riding Position		All values compared to standard riding position (hands resting on brake hoods)  [2]
Dropped	7.8%
Time Trial	12.4%
Obree	27.8%
Wheels		While these values seem massive, drag was measured for a single wheel in a wind tunnel. Therefore reduction is compared to a standard wheel not the bike/rider system. [3]
Disc Wheel	70%
Aerodynamic spoked wheel	60%
Frame type
Lotus Monocoque frame	16%	Value of aerodynamic reduction with rider. Frame type now banned by UCI [1]
Clothing
Lycra Suit	11%	[4]
Aerohat	7%	UCI regulations now require headwear to be protective – aerodynamic helmets still effective
Exchange trousers and jacket for tight fitting clothing	30%	[5]
Exchange wool suit for lycra	7.6-8.4%	[6]
Exchange polypropylene suit for lycra	9.8-10.5%	[6]
Drafting
Directly behind rider	49%	[7]
30 cm wheel gap	38%	[8]
2 m wheel gap	27%	[8]

What’s clear is that many of these values are quite significant and illustrate why the UCI felt compelled to ban some of these innovations (Graeme Obree’s riding position and the monocoque frame). It is easy to see the magnitude of advantage that can be gained by adopting as many innovations as possible. It is after all Dave Brailsford’s ‘aggregation of marginal gains’ which is thought to be a great contributor to the success of British cycling.

Power and speed

To illustrate the effect in a typical cycling scenario I’ve used a model on the cycling power lab website. There are a huge number of factors which influence rider performance – this model allows us to control the environment very strictly to create a number of ‘what if’ scenarios. I’ve chosen a very simple case with:

• Rider + bike mass = 85 kg
• 0% incline
• no wind

I’ve then used the model to calculate two scenarios based on % aerodynamic drag reduction from the ‘standard riding’ position (a rider riding with their hands on the top of the handlebars).

1. The power required to maintain a speed of 40 kph
2. The speed which can be maintained with a power output of 400 watts (this is a HIGH power output which can only be realistically maintained by high level cyclists for any period of time).

While the model doesn’t account for everything, the graph above does illustrate what advantage can be gained from reducing aerodynamic drag. When speed is kept constant, power requirement reduces considerably. This isn’t the case with riding speed at a constant power output. The fact that aerodynamic drag is proportional to speed squared makes these gains much more modest. However, they’re enough for considerable winning margins over distance.

If you’re a time trialler or keen cyclist you may find the power model useful. It allows you to calculate cycling speed based on power output and aerodynamic drag – great for testing different equipment scenarios and expected gains in speed.

Despite the considerable advantages which can be gained, the high tech approach isn’t for everyone. Purists argue that it allows ‘lesser’ cyclists to compete with records set by cycling greats such as Eddie Mercx; disc wheels and monocoque frames allow for higher speeds at lower powers. I have to admit, despite the science and the compelling evidence it will be a long time before I’m ready to give up my one-piece woollen racing suit.

Simon Choppin

P.S. For anyone interested in just how far aerodynamics advantage can be pushed, I encourage you to follow Graeme Obree’s latest record breaking attempt in a human powered vehicle (HPV)

http://www.cyclingweekly.co.uk/news/latest/539078/graeme-obree-s-record-attempt-gathers-pace.html

References:

[1] Hill, R.D. (1993) Design and development of the LotusSport pursuit bicycle. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 207 (4), 285–294.

[2] Grappe, F., Candau, R., Belli, A. & Rouillon, J.D. (1997) Aerodynamic drag in field cycling with special reference to the Obree’s position. Ergonomics, 40 (12), 1299–1311.

[3] Tew, G.S. & Sayers, A.T. (1999) Aerodynamics of yawed racing cycle wheels. Journal of Wind Engineering & Industrial Aerodynamics, 82 (1), 209–222.

[4] Kyle, C.R. & Burke, E.R. (1984) Improving the racing bicycle. Mechanical Engineering, 106 (9), 34–35.

[5] Pons, D.J. & Vaughan, C.L. (1989) Mechanics of cycling. In: Biomechanics of Sport (ed. Vaughan, C.L.) CRC Press, pp. 289–315.

[6] Kyle, C.R. (1991) Wind tunnel tests of aero bicycles. Cycling Science, 3 (1), 57–61.

[7] Zdravkovich, M.M., Ashcroft, M.W., Chisholm, S.J. & Hicks, N. (1996) Effect of cyclist’s posture and vacinity of another cyclist on aerodynamic drag. In: 1st International Conference on the Engineering of Sport (ed. Haake, S.J.) A.A. Balkema, Sheffield, UK, pp. 21–28.

[8] Kyle, C.R. (1979) Reduction of wind resistance and power output of racing cyclists and runners travelling in groups. Ergonomics, 22 (4), 387–397.

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Snurfing! What will be the next big thing in snow sports?

Figure 1: Snowboarder in flight (Tannheim, Austria)

In 1965 American Sherman Poppen fastened two skis together and called it “snurfing”. But why has nobody heard of snurfing? Probably because most people now know it as snowboarding. Why did it take so long for snurfing to develop into one of the most popular snow sports of the 21^st century?

There is still some debate over the inventor of the snowboard, however it is known that Poppen was the first to patent a design that reflects a modern day snowboard. A patent was filed under the name surf-type snow ski. Poppen’s design was inspired by the desire to entertain his daughter. Upon successfully achieving this, the snurfer was marketed as a kid’s toy and over 800,000 of them were sold from 1965-1969. The snurfer had a tether attached to the front of the board to provide more control to the user and did not function with bindings or purpose made footwear.

Figure 2: Snurfer patent 3378274 diagram excerpt

For the next 20 years no design improvements or new technologies were introduced and it wasn’t until the 1990s that things really took off, with a huge number of patents on snowboard bindings (Figure 3). What happened around this time to fuel an increase in snowboarding?

In a 1979 snurfer competition, an entrant arrived with a modified snurfer. The modifications were deemed illegal and the participant was placed in a new category. The competitor was Jake Burton Carpenter who would later go on to found the company Burton Snowboards.  The addition of bindings to the snurfer made the equipment more enjoyable and easier to use whilst also allowing the user more functionality.  At the same time marketing of the snurfer shifted from a children’s toy to sports equipment, professional associations were formed and ski resorts began to accept them on chair lifts.

So what will be the next big thing in snow sports?

When surfing and skiing was first combined I’m sure people thought it was a crazy idea — and here’s another one… THE HANG BOARD.  Patented in 2006 it appears to be a combination of a snowboard and a hanglider. It is easy to dismiss the idea now, but just like the snurfer it may only take some time and a few little design changes. If ski resorts were reluctant to let snowboards on chairlifts, I can’t wait till they see this!

But what do I know, we could all be hang boarding in 2030.

Further Reading and Videos

• Inventor Sherman Poppen, snurfing his way into history
• You should thank the man that built this board. His Name is Sherman Poppen- Interview 

About the Author

Brendan Lawrance is a current student at Sheffield Hallam University where he is studying a MSc Sports Engineering. He previously graduated with a Bachelor of Engineering (Mechanical) from the University of Sydney, Australia. His previous study and career has focused on mechanical design with his passion in sport leading him to seek a career in sports innovation. His sporting interests include snowboarding, football, mountain biking, cricket and running. His sporting ability has been described as ‘a jack of all trades, a master of none’, but this doesn’t stop him from having a go.

Why do the Dutch skate so fast? Speed skating: a tale of culture, courage and innovation

The speed skating events in the Olympics this weekend kicked off with a fully orange podium in the men’s 5k event. The woman’s 3k golden medal was also awarded to the Dutch. What is it with this little country that makes them so good at speed skating?

Speed skating as we know it has evolved from a way of transportation and leisure activity into a serious sport. This fast-track through history starts at the roughest days of the sport, to end at innovations that made everyone skate faster.

 

The Elfstedentocht

In 2009 a movie called “The Hell of ‘63”  was released in the Dutch cinemas. It tells the true story of an infamous ice skating event (the Elfstedentocht) in the Netherlands and how one sport can turn a country upside down. The first Elfstedentocht marks the switch of ice skating into speed skating; with the first tours even allowing multiple winners at the same time. Invented in 1909, this 118 miles long tour on natural ice is feared as well as beloved. The length and setting of the course ask for extremely cold weather conditions; e.g. in 1963, the weather was so extreme, only 0.74% of almost 10.000 participants reached the finish line. The skaters that day had to deal with frostbite of body parts (including the eyes); the cold cracked the ice which combined with bad vision resulted in broken bones and/or cuts from the blades. Innovations in gear, including insulating clothing, have made it safer to skate the tour since that year, with even the current king completing the tour (incognito) in 1986.

Olympics and Innovations

In 1924 the first Olympic speed skating event was held. Patents in (generic) ice skating from 1920-1929 were only 15, since then the sport has gone through an enormous growth. Innovations include the one-piece suit introduced by the precursor Franz Krienbühl in 1974; the aerodynamic advantages from this suit were huge compared to the woollen suits used before that time. This decade marks the first big increase in patents, as shown in figure 1. The 1980’s brought a rise in ice hockey and innovations in that field; while in 1984 Von Ingen Schenau invented the first official clap skate in Amsterdam. The number of patents resulting from this invention  didn’t take a great leap until the Dutch ladies all-round team proved the clap skate to be superior in the world championships of 1996.

Innovations throughout the 20^th century have had an amazing influence on the sport of ice skating. From better isolation till aerodynamic and neuromuscular advantages – speed skating is a sport greatly influenced by engineering. The golden medals earned by the Dutch in this sport might be due to a combination of a rich ice skating history, the popularity of the sport in this country and the home ground advantage of the clap skate invention.

Further readings

BBC about the Elfstedentocht 

and Public Service Broadcasting video about the same subject:

About the author