Aerodynamics is still the hottest word in road cycling, with deep section wheels, aero frames, and helmets a common presence not only in the professional peloton but also with amateur racers and club riders.
At higher speeds it is air resistance that consumes almost your entire power output. Travelling at about 20mph, up to 90% of your effort is used to overcome the air resistance, to push the air out of the way. You might think that only racers can benefit from improving aerodynamic efficiency, but in fact, most cyclists can benefit from a few aerodynamic tweaks
The latest aerodynamic equipment can cost a small fortune, though. It’s even possible to book time in a wind tunnel if you’re feeling particularly flush and want to do a proper job of reducing your drag and have results to validate the improvements.
The fastest aero road bikes
We’re not all made of money, though, but it’s possible to get more aerodynamic without spending any money.
Close-fitting clothing
The cyclist causes about 80% of the air resistance (drag) so there are significant performance gains to be had by taking a closer look at your outfit. Loose and flappy clothing just catches the wind and massively increases your drag. A one-piece skin suit can save you 29 seconds over 40km at 37kph, according to an article by Damon Rinard and John Allen.
So close-fitting clothing is good, then. Choose a jersey and shorts that have a snug fit and in particular fit really well around the torso and shoulders. It’s not just racers that benefit from close-fitting clothing, you’ll benefit during a sportive even at lower speeds because a slower cyclist spends more time on the road so saves more time.
Most of the professional teams now wear clothing that has been developed in the wind-tunnel, with aero suits (skin suits with pockets and long zips) a common sight in the peloton. But you don’t have to drop your month’s salary on the latest aero clothing, going down a size can be a simple way to achieve this.
Zip up your jersey
Riding along with your jersey or gilet unzipped and flapping in the wind might keep you cool, but it will generate loads of drag. You might as well wear a parachute. Unless you’re grinding up a steep climb below the speed at which air resistance is a factor, keep the jersey zipped up. You might be hot, but you'll be fast.
Get your head down
As your body causes most of the drag, getting your head down is a simple way to reduce drag. You’re aiming to reduce your frontal surface area, and keep your position as sleek and low profile as possible. A dropped riding position can reduce your drag by as much as 7.8% according to a study by Engineering Sport.
The drops aren’t just for the descents you know. Get your head and back down low by using the drops on the flat roads, you’ll be surprised at the difference. If your drops are hard to reach, consider putting some spacers under the stem to raise them. The more you ride in the drops the more you'll get used to the position as well. Additional core work can also be beneficial.
Alternatively, use the hoods to adopt an aero position by keeping your forearms straight and your elbows tucked in and at a 90-degree angle, this will reduce your frontal surface area. This position isn’t always as comfortable as riding in the drops, but it has the potential to be faster because your arms aren’t straight like they typically are in the drops.
- Video: Geraint Thomas finds marginal gains at the velodrome
Get narrow
The other way of reducing your frontal area is to have your hands and elbows as close together as possible. Look at any top time trial rider, like Ethan Hayter above, and you can see their elbows are close together, which pulls their shoulders down and together too, further reducing frontal area. It's not comfortable, but it's fast.
How do you know if any changes you make have reduced drag? In an ideal world, you’d be in a wind tunnel to validate the changes, or taking to a velodrome with a power meter. A power meter can be used out on the road, but controlling the variables is tricky. A simple roll down test doesn’t cost anything and can easily be repeated with just simple cycle computer required to track changes. This provides an easy way of trying different positions.
Shave your legs
Racing cyclists are famous for their shaved legs, and as much ridicule as removing leg hair can generate, the science says that smooth legs are faster. Specialized aerodynamicists used their wind tunnel to show that shaved legs can save as much as 80 seconds over 40km. So when your other half asks why you’re shaving your legs, just tell them it’ll make you quicker.
Tape up those air vents
All those vents in a cycling helmet are designed to suck in cooling air to prevent overheating on a warm ride, but if you cover them up, you have yourself an aero road helmet without spending any dosh. An aero helmet, with no vents, could save you as much as 40 seconds over a 40km course compared to a regular vented helmet, according to wind tunnel tests by Specialized.
Take a leaf out of the British Cycling book, which in 2011 provided a helmet with a thin plastic covering, to smooth over the vents, for Mark Cavendish to ride, and win, the world championships. You could get a similar result with some cling film. It might lead to overheating in warmer weather, but what price for reduced drag?
Related: Should you buy an aero helmet?
Wheelsuck
That’s right, get on another cyclist's wheel and hide in their slipstream; it’s an easy way to reduce drag. Make sure to pick a cyclist that’s bigger than you, and you could reduce your drag by as much as 40%. You may be required to do a turn at the front, though. Editor-at-large John Stevenson likes to tell a story of riding the Dallaglio-Flintoff Cycle Slam charity ride led by former England rugby union captain Lawrence Dallaglio and showing Isabella Calthorpe (future wife of Richard Branson's son Sam) how to sit behind the big man so she could more easily keep up. At 6 ft 4 in (1.93 m) and 17 st 9 lb (112 kg) Dallaglio punches a sizable hole in the air. John swears this story is about the effectiveness of slipstreaming and not about him riding with the rich and famous.
Get a motorbike to follow you closely
Okay, so we’re not actually advising you do this, but an interesting study showed that a close following motorbike can actually help to improve your drag.
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34 comments
Top tip - if you wear a squirrel suit, try shaving it first.
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The Specialized fluid dynamicists seem to be unsure about hair, and its impact upon aerodynamics. According to http://road.cc/content/tech-news/119553-video-beard-or-not-beard, it makes 0 seconds difference over 40 km whether one has a beard or not, but http://road.cc/content/news/129913-video-should-you-shave-your-legs-yes-says-science says you save 80 seconds with shaved legs. In another
PR stuntdeeply scientific investigation, http://road.cc/content/news/140018-shave-your-arms-and-ride-faster, they want to to shave your arms as well, in order to save another 19 seconds.I think the answer is clear, we need to start growing facial hair on our arms and legs!
Your legs at 85 cadence are getting a lot more air time than anything static, plus increased windspeed on the forward stroke. Marginal, but we are talking about very fine margins.
Your beard however, is not stuck out in the wind increasing drag as it is merely a leading edge for the main drag that is your body.
i can believe thier PR stunt. it isn't like they are selling you razorblades or immac.
I have no doubt that the Specialized data is reflective of reality. Ok the numbers may need further scrutiny, but I am certain that leg hair will have a significant effect on drag and aerodynamic efficiency.
Anyone that shaves regularly, let your hair grow out... keep your legs covered whilst doing this, adn then ready, whip off the tights and feel the breeze.
I think its easy to say 'its only a little hair' but its more to do with surface area and how air travels across this. Hair is designed to trap air, therefore will generate a lot of turbulence. This turbulence might not be that much in the scheme of things, but when you look at the surface area of the legs as a percentage of the whole surface area of a person on a bike, its pretty significant.
And if you need any further persuasion, those clothing manfucaturing boffins are looking at 20+ watts savings from just changing the material of skins suits... nothing to do with fit... just the material.
Thats .5mph or 60-70 secs over an hour.
Wind tunnels are not representative of reality and I am willing to bet that the effect is insignificant in the real world. The motion of a pedalling leg surely creates far more turbulence than any hairs sticking out of it.
The key words there are "looking at". How many road.cc readers are going to pay for those? Endura's Drag2Zero skinsuit is £265. Even if the material made that much difference in the lab would you or I really get that 20w out on the road? And would you notice?
Anyone interested in cda etc might like to look at Xavier Disley's tweets, this one shows 24w saved with a better arm position (which is free):
https://twitter.com/xavierdisley/status/538663678925873153
As a marketer you can produce lots of data which "reflect reality" but is still irrelevant in a given context.
The whole idea is to present some meaningless numbers from a carefully choosen scenario typically at unrealistic speed hoping that those stupid numbers of watts or seconds will get stuck in peoples's heads and will quoted in a press and on forums...
Calling time savings from shaving legs "significant" proves how effective the guys from Spesh are in brainwashing their customers.
The speeds and setups in a wind tunnel (+ 25mph) are compleely detatched from the real world of non-competing amateurs typically riding at 16-20mph.
You do realise that the 25mph(or usually 40kmph as the standard) is the airspeed not the ground speed. Therefore it is quite likely for amateurs to get to such airspeeds in windy conditions and also, 25mph on the flat isn't that difficult to do in a bunch etc.
Just my tupence
True, but in a bunch, the bunch has done the work of getting the air to move forwards for you, so the airspeed in the bunch is much lower. This makes the aero-ness (new word) of your spangly wheels and tight clothing less important.
Drop a few kilos in weight, by fasting for two days a week. You actually save money on food. You're more aero and you are probably going to be better on climbs. What's not to like?
"You may be required to do a turn at the front, though"
May?
Apparently, if you want the best aerodynamic benefit from your legs, you should shave all of the hair off apart from at the back of your legs which will promote a better and smoother air flow and transition - a bit like a calf mohican
So to summerise, cheap/free aero
Position - low an tucked up on the drops.
Stem - low as you can pointed down, match those bars!
Clothes - tight (dig out those jerseys you shouldnt fit into).
Wheel suck - never take your turn up front for pro points.
Tape that lid - vents are a sign of weakness even in summer.
Shave those legs - Because nothing is harder to explain to non cyclists why you have smoother legs than most women.
Is a beer gut more aero than a flat pack?
I have that Rapha skin suit.
I daren't wear it.
tuck in the elbows, bend your arms in a right angle, curve your back. Pretty similar to a position with aero bars.
forget disc brakes and the tons of spacers.
forget loose fitting cloting and beard
get the shallowest bar you can find (eg. itm alcor80, pro plt): set up the drops as low as you can manage. The hoods will be not that much higher.
riding 90 percent on the hoods with tucked in elbows&bent arms, and not because i want to be aero, just, because iM weak, and i found that this way i can spare a lot of effort
https://tunedintocycling.files.wordpress.com/2014/07/forearms-on-bars.jpg
assuming position like this will make pedalling in strong winds much easier. Therefore, it is quinessential for me, as my legs cannot handle that much effort
another very useful tip, but only for long flat courses with immaculate roads, no potholes and no sharp bends: rest your forearms on the handlebars, as you had an aero bar attached..
switching to narrower bars also useful..
just do not spend to much money
Oh dear, I haven't laughed so much in ages after reading this 'expert' and his 'advice'.
The reason you shave your legs is fuck all to do with aerodynamics, it's to do with preventing 'road rash'.
To anyone who hasn't yet had the thrill of sliding down the road with hairy legs after a crash; After weeks (months) of picking bits of stone out of your skin you will understand.
PROPER GUIDE TO GETTING AERO FOR FREE
1) So.......... You are a mid-life crisis male and cycling is the new thing right? A few years ago that flash motorbike you bought scared you when you got a 'tank-slap'and you sold it at a loss. Instead of spunking £6K on a carbon road bike, why not just spend £600 on a bike and lose some fucking weight! That way you can get a low position.
2) That thing at the front of the bike, yes above the forks, is called the stem. No doubt it is pointing towards the sky, with two inches of spacers underneath it. How about you turn it around so it is flat, remove the spacers and put is as low as possible?
3) That handlebar with the brakey/gear thingys attached. You could twist the handlebars so they are further down and the brake hoods do not resemble the position used by Joe Public in the 1970's.
4) Learn how to ride on drops (curly bits on the bar), properly: Elbows at 90 degrees to said setup above, chin should be close to stem, back will hurt, a lot. Also, imagine tri-bars on the tops as this is a very aero and actually comfortable with your elbows steering.
5) Learn to do sit-ups and crunches to hold said position for several hours on rollers or a turbo trainer. It will help. NB: Crunchie bars are not a training aid!
6) Check your saddle height: Can you touch the gound from the saddle? If so it is too low. Put the saddle back on the rails as far as it will go to get your back as flat as possible. Putting the nose of the saddle up by several degrees will sit you back further for a better aero postion
7) Descending; A peloton at full flight swooping down an alpine road is indeed a sight to see....... pure poetry of bike riding at it's finest. Pedal up up 30mph, get your arse off the saddle, get your chest on the flats and get you nose near the front wheel. When you hit 50mph or more use the brakes very carefully. If you get this position right there is little weight on your back wheel.... Fuck it up and.... well birds like scars (ish). You might break a few things, but you didn't scratch your bike.
8) Helmets: Up to you. Not going to work above 15mph to protect you. Freedom of choice. The only ones that work are T/T helmets in terms of aero.
9) Clutter: Do you really need all that crap on the bars when trying to get aero? Lights fair enough, but mobile 'phones, Satnav and fuck knows whatever is slowing you down. If you have to have a computer then something small and just display 'average speed'.
10) Last one on my rant about aero: Does it really matter if you are a social cyclist? Doing a Sportive and having a chat with others does not mean you need an aero bike. If you want speed then comfort will go out of the window: Numb nuts, feelings lost in both hands, knackered knees etc. I'm sure anyone who is a certain age and has raced will agree.
What do I know...........?
Shaving your legs doesnt "prevent" road rash. It just makes treating it easier.
DO NOT PUSH YOUR SADDLE BACK AS FAR AS IT WILL GO.
Your saddle position is governed by your thigh length such as with the pedals at 3&9 o'clock a plumb line from the front of your knee falls in line with the pedal axel (traditionally accepted way of setting up, subject to personal preference).
Pushing the saddle back will likely cause you horrible knee problems and be very inefficient thus making you slower. I for instance use a 0mm setback post but could be using a 25mm setback if I had longer femurs. Also because it's sexier.
Instead consider slamming your stem (gradually over time whilst working on touching your toes) and or using a longer stem.
I will further add that your saddle should always be flat to prevent possible conception problems, and because that's how they were designed to be used. Unless timetrialists have it all wrong.
Why flat? With traditional saddles I prefer to have them pointing down at the front – to reduce pressure on the perineum and put it on my sit bones instead. It's far comfier this way and feels like it's preserving my fertility.
That said, I use an Adamo for 90% of my rides nowadays, which completely eliminates the pressure in the middle. Problem solved!
Huh? Where did you hear that? Have you tested it? It's been quite conclusively demonstrated that shaved legs are several watts faster. But, unfortunately, they won't prevent road rash.
The idea that the reference is to "Specialized's aerodynamicists" who have "data" that suggests that shaved legs reduces 80 seconds or so over 40km, then in the next thought be suggesting that things like taping up vents will save 40 sec... Utter nonsense.
Taping up vents - yes, I can believe that would save something like 40 sec over 40km (realistically, probably less than that, but there is air moving through the helmet, so it's believable).
But shaving the legs saving 80 sec on the same distance???????
If your BS meter doesn't jump up and start flashing brilliant red lights aimed squarely at "Specialized's aerodynamicists", then you have no real analytical skills.
Look at your legs. Now look at your helmet. Look again at your legs and how much area is taken up by your leg hair. Now look at how much area is taken up by your helmet vents. Look at your legs again. If you're still not getting it, shave your legs and look at the amount of hair on your legs. Compare with your helmet vents again......
Specialized's "aerodynamicists" are well known for taking spotty data below the threshold of accuracy for their test, applying it in questionable ways that work well with confirmation bias and a total lack of common sense.
Never met an actual fluid dynamicist that gave a whisper of credence to those Specialized videos...
Hair has a huge surface area. The whole purpose of it is to trap air to keep you warm. I have no reason to doubt it has twice the drag of a few helmet vents.
I thought long compression socks were all the rage these days. Are they that expensive? I have no idea (not raced for 10 years).
How many fluid dynamicists do you bump into every day?!
I would agree that many of Specialized's claims are outrageous and do them no favours, but would also agree that a hairy leg can trap a huge amount of air, and that the surface area would indeed be higher than a couple of helmet vents.
Very few. They're a lubricious lot.
6a) If you haven't trained for a significant time to achieve points 2 to 6, ensure you have a chiropractor on speed dial.
Staring at your stem is actually aero, but it's also dangerous.
Sitting on the crossbar downhill is also aero, but again dangerous.
Don't flare your elbows out to the sides.
...and the knees. As seen at every sunny weekend
Don't spend any money on close fitting clothing, just eat chocolate bars until fill out your baggy clothes.
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