Sorry for the bad link. I fixed it...sort of.

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Jim Manton / ERO Sports

Duathlete using Velotoze calf sleeves here. Looking forward to seeing your calf sleeve video to judge whether Im looking like a dork for no particular reason or if they are indeed faster. ;)

Thanks for doing these tests - very interesting!! Looking forward to the sleeve testing.

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Regards, Richard

That was interesting! I've used the Silca aero socks and can confirm they are comfortable on the run. I found the rule 28 socks were fine for cycling and they didn't slip down, the gripper was almost glued to my leg when I took them off.
I look forward to you testing the calf sleeves, I used the Rule28 ones at IMLP and they were pretty good comfort wise but would be nice to put an approximate number on the savings.

Why would calf sleeves work well less often compared to socks? Are you comparing different brands and styles that could account for the difference rather than just sock vs sleeve?

another vote for Velotoze calf sleeves

Most of the calf sleeves are pretty much the same design these days. We've been testing three different brands with similar designs, but one brand has certainly stood out. Mostly, I believe, because they're simply longer than the others. I might try to get my hands on some Surpas ones and sneak those into testing only because they're different and the limited testing I've done with them indicate they're pretty darn good. The other issue I see is if the sleeves are too small for your calves, they stretch out too much and the ribbing is flattened limiting their value in creating turbulence.

No matter what, by putting on sleeves, or socks for that matter, you're increasing surface area, so creating the proper amount of turbulent air is important. Too little, or too much, and the benefit is not only gone, but you've likely increased your overall drag.

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Jim Manton / ERO Sports

Thanks - but my question was more in regards to your statement about socks working for a wider range of people than sleeves. That doesn't make sense to me if you think of a sleeve as being just a sock with the foot cut off - all else being equal. That's why I asked about apples to apples comparison. One brand of sock compared to a different brand of sleeve introduces other variables that you aren't controlling for. It seems more likely that the sleeves you tested might have differences from the socks, not simply because they are sleeves, but because of the design, fabric, fit, etc.

It makes sense when you consider right about where the socks cut off, the upper third of the lower leg, is where most athlete's shapes differ. Air is going to flow differently for those shapes and it's difficult to design for. Most calf sleeves cover that area, but are the same design with the same materials, so they mostly test the same. If one doesn't work for an athlete, chances are the others won't work either. When they do work, they make a bigger difference than socks, which is logical. Amongst those similar designs, one particular product seems to stand out from the others, but again I think it's only because they're longer and cover more area. Primarily, though, they're the same design with the same ribbed material. On the other hand if, say, a specific brand doesn't test well for an athlete, then none of the similar designs seem to work either. There is one design, however, that might eschew all of that and work for pretty much everyone. I just need to test more athletes before I'm willing to make that judgement.

The socks have certainly surprised me. I didn't expect them to work on as many athletes as they have, and in the end maybe is just the sample size I have which is somehow skewed. I thought for sure I'd be able to identify why they work on some people and not others, but measuring tibial length vs calf diameter doesn't seem to be yielding any answers. Talking to Josh Poertner, he finds the same thing we have. Every once in a while, they won't work but there seems to be no rhyme or reason why. I, of course, give some possibilities in the video, but have no data to support any conclusions. I just have to tip my cap to Josh and his crew for making a great sock that seems to work for most.

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Jim Manton / ERO Sports

Rule 28 hater here. Got an XL pair as a 5’ 10” tall 160lb rider and they were outrageously painful to get up on my calfs then even ripped the upper elastic on second use. I email them and just got some cookie cutter nonsense response. I would have appreciated another pair sent my way.

I’ve owned Rule 28, Castelli, and various aliexpress socks. All 95% same look. My best has always been the Aerocoach shoe cover. For ease of use more of a TT thing than a triathlon thing. But if the upper is similar for their sock I should buy a pair.

Did you see the tall compressport socks Laidlow used in Kona? They don't have the turbulators on the back,. But go up to the base of the knee.

Do you suspect the turbulators on the back make that much of a difference compared to a flat back sock to offset the imagined benefit of the taller sock?

Not sure I agree that most calf guards are the same design at this point.
Can think of 3 very different concepts:
Rule 28 Aero Calf Guard – Classic ribbed fabric (most common).
Nopinz Flow Guards - a big trip seam on each side of the shin
Huub 3:Sixteen Aero Calf Sleeve - smooth outer fabric & ribbed underlayer


For what it is worth, on me the classic aero ribbed fabric was natural to shaved legs. Flow guards were slower. Have not tried the Huub 3:Sixteen but would like to, though certainty
not cheap.

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First of all thank you Jim for sharing.

That's what I thought of straight away, and I did not get an answer to it yet.
When those socks avoid drag so well, why are they not cut of higher? I can imagine that the drag savings are then proportionally higher! (if they are so easy to put on in T1, as you mention, 10 cm more will not be a huge problem either)

I tested CEP calves, also classic aero ribbed fabric. Did also make no difference for me compared to shaved legs.

$30 for socks are not that expensive, and as I always put on socks in T1 I could imagine buying those Silcas. Although I'm sceptical they will help, after my CEP test.

The socks started out really as a technology demonstrator moreso than a product. I had serious egg on my face a few years back after I pushed one of the worldtour teams to start racing everything on TT socks The clothing sponsor shifted all of the team sock to these and then within the first 4-5 weeks of the season the riders nearly revolted due to the socks falling down in the rain and other frustrations. So I developed this concept for a knit aero sock and spent a few weeks in Italy working on how to get the knitting machines to actually do it.. anyway, the sock was done in this really obvious way to show clothing brands that you could approach the performance of a ribbed lycra sock with a fully knit one.

We patented this and currently license the patent one of the big clothing brands with the terms that we have the right to continue producing for our own customers. So that's how the sock came about.

Huge thanks to Jim for doing this testing and putting out this content.. It is always satisfying to see something you worked really hard on go out in the real world and not only perform as intended but also really work for real people.

We don't make them any taller for two reasons, One: my aesthetic sensibilities would keep me from sleeping at night! Two: the downside of the knit construction is that you are knitting the foot and upper with a fixed number of needles/yarns, so as the sock is stretched to larger circumferences, the surface roughness of the material increases dramatically as the weave is stretched open on the upper section of the leg. The relatively large differences in circumferences of the upper leg makes that a much better region to use the textured lycra type fabrics as they can be patterned and then sewn together in a way that allows for localized stretching of the material to remain relatively constant throughout, which in turn keeps the surface texture of the material constant throughout.

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http://www.SILCA.cc
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For UCI racing there's a max allowable height.

thanks. And also josh thanks for your explanation.

I've got 45 in Europe. Shall I order L (42-44) or XL (45-48)

I found compressport tall socks are very hard to put on during T1 when feet is wet.

I've seen multiple brands work for multiple people, 1 brand work out of 3-5 tested, no brands work, can't say that i've seen every brand work unless they tested 1-2 pair. Would have to dive through all my data on that.

It's so iffy, at least in the probably 40+ different athletes I've tested socks on. Hard to say if they will help or not.

A lot of people are choosing them, hoping they help. It will help some of those, hurt others. Hard to know which way the coin is going to flip sometimes

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

If you're going to wear socks anyway, i.e. bike racing, would you say it's better to wear something like the silca aero sock than a normal sock? Especially if you have relatively wide lower legs?

This whole discussion on turbulators, and explanation from Jim, remind me of the 2014 ST April Fool's page:

https://www.slowtwitch.com/Lifestyle/Hair_Improves_Performance_4255.html

We're going to take 10 guys and test first completely unshaven, then shave down to stubble, then completely shave in front with stubble from the apex back, and then completely shaven. Stubble from the apex back could be best, but it will depend a lot on each athlete's hair follicle density. Still, it will be fun to see the data and what we get. No chevron's though.

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Jim Manton / ERO Sports

Jim what speeds were you testing? Does the AeroLab sensor have a way to check or verify head/body position?

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Heath Dotson
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