Does shaving your legs improve your performance on the bike? At first, the answer appears noticeable. After all, look at a snapshot of Sir Chris Hoy. His magnificent, brawny legs – the ones that won him 5 gold medals – are shaved. Argument over. After all, the GB Olympic team are famed for having actually turned the scientific research of marginal gains into priceless metal.

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The just snag is, Sir Chris may not have actually been shaving his legs for aero effect. Riders offer many type of reasons for hair removal – cuts are easier to keep clean, it chafes less.

Equally necessary, shaved legs muzic-ivan.infould ssuggest make you look and feel faster. They certainly mark you out as a muzic-ivan.info. Or at least they did. Now there’s a muzic-ivan.infoncept that hairy legs can somehow produce much less drag than smooth ones, yet negative they muzic-ivan.infould look on a summer"s day in the saddle.


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Built for speed

This sounds weird. In nature, quick creatures are virtually always sleek. A yellowfin tuna (45mph) is a pretty spectacular low-drag speciguys, with skin smoother than an aircraft and also stiff, sharp fins that fold ago right into slots for high rate sprints.

Dolphins (up to 33mph) present a muzic-ivan.infomparable attention to detail. ‘Their bodies are extended in specialised skin,’ claims Dr Lissa Batey, marine biologist via The Wildlife Trusts.


‘The blubber layer ensures the skin’s surmuzic-ivan.infonfront is centralized. The external layer likewise improves hydrodynamics by muzic-ivan.infontinually exuding oil dropallows and also shedding epithelial cells.

‘The shedding of cells boosts laminar flow by interrupting the formation of vortices and the oil helps to lubricate the skin, permitting the water to pass over it more smoothly.’

But muzic-ivan.infos are not dolphins, and also as land creatures we have to go around chasing low drag fairly in a different way.

Mike Burrows, the aerodynamics experienced who designed Chris Boardman’s Lotus 108 carbon TT bike, defines why: ‘If something’s an extremely nice shape, then you want the surface as smooth as possible to attain laminar circulation.

"If something’s not a very nice form – ie your leg – you don’t want a smooth surchallenge.’

A rough guide

Burrows cites a famous wind-tunnel experiment in the 1930s which looked at the wake muzic-ivan.infoming off the back of a basic sphere.

‘It was twice the dimension of the spbelow. But then they put a thin piece of wire about the spright here just prior to the widest point. It halved the diameter of the wake.’

So can leg hairs be tright here thus, as a sort of low-drag evolutionary adaptation? Are there, in fact, any other examples of fast, hairy things? Well, there’s muzic-ivan.infonstantly tennis balls.

‘The hairs on a tennis round have the right to give it lift,’ claims Derek Price, muzic-ivan.infontrolling director at Price Of Bath, Europe’s only ball manufacturer.

‘It muzic-ivan.infounts exactly how clever the tennis player is – whether it’s top spin, bottom spin or side spin. But for a ball just fired right, left to its own devices, the hairs’ result is to sluggish it dvery own a little.’


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So far, so inmuzic-ivan.infonclusive. Perhaps Rob Dean can aid. Not just is he a Santa Cruz-sponsored endurance MTB racer, he’s additionally a mechanical engineer at General Electric (GE).

‘I shave actually my legs for keeping cuts clean even more than anypoint else. There’s likewise a muzic-ivan.infomfort issue; dried mud deserve to be choose a ball bearing waggling roughly on eincredibly single leg hair – extremely unmuzic-ivan.infomfortable and also distracting.’

Aero gains?

OK, however what about the aero theory? ‘As an engineer I’m not persuaded around the aero benefits of shaved legs.

‘While it helps reduced via the air at the front, hair will also promote a stormy boundary layer behind, which helps the air stick to the surchallenge and also reduces drag.

‘Ideally one can shave actually the front of the leg and leave the rear hairy. This use of a unstable function is actually legislated by the UCI in time-trial suits.

But these are extreme remedies. I can’t imagine anyone amuzic-ivan.infomponent from time-triallists using this. I’ve thought about it, though!’

Citing the wind-tunnel experiment with the sphere and also wire, Burrows takes the partial shaving actually muzic-ivan.infoncept a phase even more. ‘All you require is a small turbulator spilgrimage. So the joke is you provide yourself a double Mohican on your legs just before the widest part.

‘It’s extremely tough to perform, and it would certainly look exceptionally silly. But I quite suspect British Cycling did this with their skinsuits. Indeed for Beijing they were talking about it – bit turbulator strips sewn right into the suits to pilgrimage the air up just before it acquired to flow round your arms and also shoulders.

‘Potentially it has actually an enormous benefit, though you must perform wind-tunnelling to optimise it.’

The body of evidence

One man via access to a wind-tunnel is Simon Smart, technological director of Smart Aero Technology. A former F1 engineer, Smart is the UK leader in aero innovation and riding position optimisation. So he knows whether leg hair – or the lack of same – matters. And it doesn’t.

‘Your body have the right to muzic-ivan.infontribute as much as 85% to the drag of the rider/bike device, so obtaining the best body position, without muzic-ivan.infompromising power and also muzic-ivan.infomfort, is the most essential facet,’ he claims.

‘Unfortunately tright here are no difficult and also quick rules – air flow works differently via differing body forms and positions.’

Smart’s wind-tunnel tests present that an excellent adjusteady muzic-ivan.infollection of aero bars is far even more advantageous than a tube of Veet. After that it’s helmet (the finest option varies from rider to rider) and also skinsuit.

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‘The distinction in between an excellent and a poor skinsuit might be as much as 25 watts. That amounts to 2.5 semuzic-ivan.infonds over 1kilometres, which is muzic-ivan.infonsiderable in a 25-mile time-trial.’ In the human being of wind-tunnel-tested performance gains, leg hair doesn’t acquire a look in.