Is there a measurable benefit to wearing aero socks?

Question: Is there a measurable performance benefit to wearing specialized aero socks for non-elite cyclists? —Joe P. 

RBR’S STAN PURDUM REPLIES: The answer is yes, but your question takes us into the realm of “marginal gains” — the idea that significant overall improvement can be achieved by making many small, incremental advances in numerous areas of cycling (such as gear, kit, nutrition, etc.). That said, there does seem to be enough potential gain from wearing aero socks to consider adding them to your cycling attire even if you make no other tiny gains in other areas.

There are reports of wind-tunnel testing which indicate that while results vary with the rider and sock brands, some cyclists save as much as 8-10 watts of effort when wearing aero socks. Some may save only as little as about 2 watts, but almost everyone tested apparently saves some. If you are an average fit cyclist, you may be capable of producing 250-300 watts for several hours, so a savings of even 10 watts is indeed marginal, but it can sometimes be enough to keep you from being dropped by faster riders. 

Here is a narrative of wind-testing commissioned by Sockeloen, a Dutch maker of high-performance cycling socks. A link within the narrative will let you download the actual research report from Eindhoven University of Technology. 

Sockeloen’s testing was done on a rigid manikin, so the legs were not moving in the wind, which seems far from real-world conditions, but the wind-tunnel testing done by Rule 28, another sock manufacturer, used a live rider with legs pedaling. You can read their report here. (Stay on the international site to which the link takes you; the USA site apparently does not include the report.)

Both sock makers tested their own socks against those of their competitors, and perhaps not surprisingly, found their own brand to be best. Make of that what you will.

The key factor of aero socks is their textured surface, which reportedly functions similarly to the dimples on a golf ball, allowing the air flowing around our legs to hold the leg surface long enough to leave a smaller low-pressure area of drag behind them. (To visualize this, see this video, starting at the 2-minute mark.) And the fact that most professional bike racing teams now issue this specialized hosiery to their riders is testimony to the belief that the gain, though marginal, contributes positively to the overall efforts of the riders.

You asked if non-elite cyclists can have a measurable performance benefit from aero socks. Presumably they can, but perhaps the question should be, is that marginal gain worth the money those cyclists would have to spend to receive that benefit? Compared to regular socks, aero socks are expensive — several brands cost about $40 per pair, though you can find some for less (or, you can spend over $1,000 for a custom-made pair from Sockeloen!) 

Your riding goals can be the deciding factor. If you usually ride by yourself with no intention to keep up with faster riders, then the cost of these high-tech socks is probably too high. But if you’re planning to hang as long as possible with some fast riders, the expense may be worth it, as a savings of even 5 watts with each turn of the pedals will allow you to go fast a little longer before fatigue sets in.

Another way to look at the price of aero socks, however, is to compare them to the cost of other aero garments, such as time-trial helmets and skinsuits. In that comparison, the socks’ cost per saved watt of effort is much cheaper.

Or, for no cost at all, you could simply shave your legs, a procedure that, according to this wind-tunnel report from Specialized, can save you as many as 15 watts.

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Stan Purdum has ridden several long-distance bike trips, including an across-America ride recounted in his book Roll Around Heaven All Day, and a trek on U.S. 62, from Niagara Falls, New York, to El Paso, Texas, the subject of his book Playing in Traffic. Stan, a freelance writer and editor, lives in Ohio. See more at www.StanPurdum.com.