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Want to ride faster? Hunker down on the hoods, say researchers

New research confirms riding with your forearms horizontal is more aerodynamically efficient than using the drops

A paper published by the Institution of Mechanical Engineers says that gripping the hoods and keeping your forearms horizontal can reduce the required power while cycling by 13.4%, while lowering your eyes and head can actually increase drag when you are using the drops or short handlebar extensions.

The findings are contained in a paper titled Aerodynamic performance and riding posture in road cycling and triathlon, by Nathan Barry, David Burton, John Sheridan, Mark Thompson and Nicholas AT Brown.

The testing was done at the Monash University Wind Tunnel in Melbourne, Australia, with a constant wind speed of 12.5 metres per second (45km/h, or about 28mph) and the rider aligned with the airflow at a yaw angle of 0°. In other words, the bike and rider weren’t subjected to crosswind.

The researchers tested nine different postures: five with the rider’s hands on either the hoods or drops, and four more with the rider using short-reach aerobars. These aerobars were of a type that can be used in draft-legal triathlon, not extending beyond the brake levers, but you can’t use them for road racing.
 

The results

Okay, let’s cut to the chase. The researchers used a normal hands-on-hoods ride position as their reference posture, and that was the position that created the highest drag. The power required by the bike and rider they used, based on the above conditions, was 430 W.

Moving from the hoods to a traditional drops racing posture resulted in quite a small saving, bringing the power required down to 417 W.

Moving into a posture on the drops but with a crouched torso – with arms bent to lower the torso angle – brought the power required down to 385 W.

As mentioned up top, gripping the brake hoods while keeping the forearms horizontal resulted in a 13.4% reduction in required power compared to the reference posture. In this position, the power required was 372 W, easily lower than either of the postures measured with the hands on the drops.

Our picture of Niki Terpstra doesn't quite show this position. He's gripping the hoods and his forearms are angled quite low but they're not horizontal. 

The findings fit with what we were told by Jurgen Falke, Merida’s Head of Design, much earlier in the year when discussing the Merida Reacto Evo Team. He said that their testing showed that the most aerodynamically efficient position you can ride in without aerobars is with your hands on the hoods and your forearms flat. I was sure we’d included that little nugget in one of our stories, but I can’t find the reference, so maybe not.

Of course, you might have suspected this yourself from just going out there and riding, but these results confirm it.


Aerobars

Not surprisingly, the researchers found that the power required was lower still when using the aerobars, although that's not an option in road racing. In a typical aerobar position, as used in draft-legal triathlon, the power required dropped to 365 W, then down to 358 W with the rider’s head lowered and shoulders shrugged.

The lowest power required was 363 W – a 16.7% reduction over the reference posture – and that was while the rider was using the aerobars with his head tucked between his arms, although that might not be a realistic position for riding out on the road.

Interestingly, when the rider lowered his head while using the drops with a crouched torso, the power required rose significantly from 385 W to 403 W.

“This refutes the perceived aerodynamic advantage assumed for the common practice of athletes dropping their head in periods of high intensity,” say the researchers.

However, they acknowledge, “It is possible this effect is caused by the presentation of a more bluff head/helmet to the flow and may be associated with the geometry of the test helmet.”


Time saved

If you translate all of that into time savings, the researchers say that on a flat 40km course (about 25 miles) with little wind and the cyclist riding solo at a constant power output of 300 W, he’d save about 45secs by swapping from riding upright on the hoods to riding on the hoods with horizontal forearms.

The paper was published in the Proceedings of the Institute of Mechanical Engineers, Part P: Journal of Sports, Engineering and Technology. You can read the full paper, which is much, much more detailed than this short article and includes a description of the testing methodology, here

Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.

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38 comments

Avatar
stealth | 10 years ago
0 likes

How about on the drops with flat forearms? Just like in the picture of the VERY SPECIAL Tester in the B&W photo...

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Flying Scot replied to stealth | 10 years ago
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stealth wrote:

How about on the drops with flat forearms? Just like in the picture of the VERY SPECIAL Tester in the B&W photo...

I only ride vintage, withe the saddle about an inch above the stem and yes, it works, but you can't lift your head in that position.

And your knees hit your chest.

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notfastenough | 10 years ago
0 likes

Horses for courses - giving it berries on the fast section back home after a club run, I know that my mate will be on the hoods, forearms horizontal, and he's flying. I've tried it, but for me in the drops definitely equates to less effort at the top-end.

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cub | 10 years ago
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I think all this shows is that modern Pros have their handlebar positions far too low. If the drops aren't the most aero on the flats then really they aren't very much use at all.

Look at Terpstra's position, even on the hoods his forearms still bend down he needs to raise his handlebars to at least allow them to be horizontal in the hoods, I'd go even further and say raise them another 5-10 cm to allow him to get a horizontal in the drops and allow the hoods to be useful for climbing. Older riders had it right.

//www.classiclightweights.co.uk/riders/engers2.jpg)

Modern riders from pros to sportivists seem to thing slamming a stem=more aero when in fact its all about how flexible you are .

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RobD | 10 years ago
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As others have commented though, it's only a useful position of you can actually maintain it comfortably, and breathe without restriction while also getting low and aero.
I suppose it just goes to show that just because some of the pros do something, doesn't mean it's the best way for others.
Just one more reason to make sure you set your bike up properly too.

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crikey | 10 years ago
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Hmmm.
If your bike setup doesn't allow you to get low anyway, I suspect that flat arms vs drops will have little impact.

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stenmeister | 10 years ago
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I don't care too much about whether it makes you faster by x amount, I just like riding like this when on a nice straight road.
Hoods for climbs, drops for downhills. Bike riding has so many options and it all goes towards making it fun.

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redmeat | 10 years ago
0 likes

This isn't new news.

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shay cycles replied to redmeat | 10 years ago
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Not only is it not news it is also not entirely correct.

I'm not disputing the wind tunnel test in itself but I am disputing the sample size (and indeed drawing attention to the size of the sample rider).

For a tall ride e.g. Tafi the on hoods flat forearms and flat back is more aerodynamically efficient (in a straight line) as shown in the test. However for smaller riders to achieve a flat back and forearms is actually achieved on the drops (Mark Cavendish for example).

As others have said the drops are used for other reasons as well, riding on the drops lowers centre of gravity, gives a secure relaxed hand position and ready access to brakes which is why you'll see riders on the drops through corners in criteriums and winding descents.

My point?

One size, or indeed one position doesn't fit all.

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crikey | 10 years ago
0 likes

Spinaci bars.....

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chokofingrz | 10 years ago
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The next invention will be "reverse aerobars" - supports that stick out backwards for you to rest your elbows on.

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crikey | 10 years ago
0 likes

Another one, and note the narrow drops...

//www3.clikpic.com/cyclesportphotos/images/_CSP4961.JPG)

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Flying Scot replied to crikey | 10 years ago
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crikey wrote:

Another one, and note the narrow drops...

//www3.clikpic.com/cyclesportphotos/images/_CSP4961.JPG)

Yes, someone who eschews fashion and really knows his stuff. GO.

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Must be Mad | 10 years ago
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Its been well known and documented for years the the 'horizontal arms' from top of hoods is a bit more aero than 'on the drops' (assuming the head and torso position is the same).

I'ld also add that the 'horizontal arms' position also opens up the lungs more and aids breathing - which helps with longer sustained efforts.

the drops are still better for precise handling, breaking and also better for sprinting.

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monty dog | 10 years ago
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Andrea Tafi circa 2000 - epitomised the flat arm and flat back position:

http://drunkcyclist.com/wordpress/wp-content/uploads/2010/11/Andrea_Tafi...

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ajmarshal1 replied to monty dog | 10 years ago
1 like
monty dog wrote:

Andrea Tafi circa 2000 - epitomised the flat arm and flat back position:

http://drunkcyclist.com/wordpress/wp-content/uploads/2010/11/Andrea_Tafi...

Now THAT is a flat back.

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Quince | 10 years ago
1 like

+1 on the bar width conundrum. I'd like to see some wind tunnel tests done on that.

Of course, it's hard to factor the effect on breathing narrowing the bars would have in a wind tunnel, but it'd be interesting to at least see the aero figures.

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crikey | 10 years ago
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No, but this kind of 'marginal gain' does tend to see the light amongst those who do sportives.
See also electronic gears, deep section wheels, aero helmets, etc.

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The _Kaner | 10 years ago
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Why all the negative comments regarding sportives (or indeed sportive freds)...anyone that ride a sportive not good enough....???

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ajmarshal1 replied to The _Kaner | 10 years ago
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The _Kaner wrote:

Why all the negative comments regarding sportives (or indeed sportive freds)...anyone that ride a sportive not good enough....???

Not at all. i ride a few myself. It just amuses me seeing riders with bars higher than their saddles in their Giro air attack shields 'getting aero' at 12mph.

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thegibdog | 10 years ago
1 like

Not really surprising that presenting a smaller frontal area will generally mean less drag. There are a lot of other factors that influence this though, it'd be interesting to see how different bar positions and widths would change these results.

The majority of the peloton adopt the flat forearms on the hoods position when on the front, being on the drops is better for handling when it comes to cornering and descending though.

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mikroos | 10 years ago
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So... Should I chop the drops of my handlebars and leave just enough to mount the levers?  24

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crikey | 10 years ago
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Quote:

Like so many other things ("The Rules", too-skinny tyres, special energy drinks, integrated headsets, pressfit BBs, etc.) it just goes to show how many cyclists are victims of fashion and not good at dealing with reality

Um...
The Rules are an obvious piss-take; it's only people who don't understand that who get annoyed by them.
Integrated headsets and press fit BBs are manufacturing shortcuts, nothing to do with fashion. If you buy it, they'll build it.
Too skinny tyres are an historical thing and we get it now...
Special energy drinks? yes, I'll give you that one.

I do agree with this bit: " how many cyclists are victims of fashion and not good at dealing with reality", but that's an entirely different argument.

The whole flat arms=more speed thing doesn't take into account that the rest of your position needs to be as aero as it can be too. I can't wait for the change in fashion where everyone tries to ride on the hoods with flat arms while sitting up like a butchers boy....

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ajmarshal1 replied to crikey | 10 years ago
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crikey wrote:

The whole flat arms=more speed thing doesn't take into account that the rest of your position needs to be as aero as it can be too. I can't wait for the change in fashion where everyone tries to ride on the hoods with flat arms while sitting up like a butchers boy....

This. 6cm spacer stacks, flipped stems and then assuming the Boonen position to get aero, the Sportive Freds will love it.

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CanAmSteve | 10 years ago
0 likes

Like so many other things ("The Rules", too-skinny tyres, special energy drinks, integrated headsets, pressfit BBs, etc.) it just goes to show how many cyclists are victims of fashion and not good at dealing with reality

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crikey | 10 years ago
0 likes
Quote:

This also shows the so-called experts that descending in the drops for "aero" purposes is bs as well, like I have maintained for years...

It's hard to get the average mupp, oops, I mean statist to understand many things in life... Rolling Eyes

Having looked at pictures of your bicycle, with your seat pushed forwards on that in-line post, and the riser stem, I wonder if you have difficulty bending over far enough to reach them?  3

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manmachine replied to crikey | 10 years ago
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Yeah that's it! I can't reach them...that's why I don't use them... You got me.
Ugh.  29

Now if you you really were astute, you would have realized that the closer the delta of the bar-saddle drop, the easier it is to get in the drops. But alas...
well, you know.  3

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manmachine | 10 years ago
0 likes

This also shows the so-called experts that descending in the drops for "aero" purposes is bs as well, like I have maintained for years...

It's hard to get the average mupp, oops, I mean statist to understand many things in life...  29

Avatar
ajmarshal1 replied to manmachine | 10 years ago
0 likes
manmachine wrote:

This also shows the so-called experts that descending in the drops for "aero" purposes is bs as well, like I have maintained for years...

It's hard to get the average mupp, oops, I mean statist to understand many things in life...  29

Descending in the drops has far more to do with stability, control and being in a position to use the brakes properly than it does with being aero.

I'm not entirely sure that this whole debate is a revelation to many people.

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manmachine replied to ajmarshal1 | 10 years ago
0 likes

 29  29  29
Like I said...it's awfully hard to get a STATIST to understand anything OTHER than what he or she has been conditioned to buy...so sad indeed.

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