Rule 33 isn’t bunk after all

[jrenaut]

New wind-tunnel tests find surprising gains in cycling efficiency from leg-shaving.

As I don’t race (and because shaving my legs would probably require a belt sander), I don’t shave my legs. But I’ve always been curious how much difference it actually makes. Seems like a lot of other things would give you a much bigger boost with much less stubble. But if it’s really 7%, that’s significant.

Topic

[Geoff]

This is another reason why I was meant to ride a bike. See, guys generally worry about going bald on the head. My hairline has receded hardly at all over the years, while my legs have gone nearly bald. But I get to claim I shave them because I’m a cyclist!

[cyclingfool]

I’m not buying it w/o neutral scientific investigation. Plus, here’s what I don’t get. What are they comparing to as a baseline? And, of course, he’s faster. He just had a long break and ate lunch. Am I the only one that finds this fishy? Under more controlled methodology with a larger sample size, I’d maybe buy some performance improvement, but this still seems like bunk to me.

I remember hearing an explanation fo the shaving thing this summer that finally made sense to me — namely that it was about making road rash easier to clean and less painful following encounters with the “deck”.

OTOH, if I can put my skepticism aside, it would help to explain why I’m such a slow cyclist!

[Steve O]

@cyclingfool 94066 wrote:

Am I the only one who finds this fishy?

OTOH, if I can put my skepticism aside, it would help to explain why I’m such a slow cyclist!

And for me, given the asymmetry of the hair on my legs, it explains why I tend to ride in circles.

[mcfarton]

Still not going to shave my legs.

[hozn]

When I saw this post, I was sure that the link would be to the recently done Specialized wind-tunnel test. As it doesn’t appear to be that test, here’s the link: https://www.youtube.com/watch?v=DZnrE17Jg3I

This is wind-tunnel testing (not measuring speed of the athletes per se) and the science sounds reasonably solid. It saves more time over the 40k than an aero bike frame or most of those deep carbon wheels.

But of course, the only real reason to shave your legs is rule #33.

[PotomacCyclist]

The Specialized test showed that the time savings depends greatly on how hairy you are, i.e. where you measure on the Chewbacca scale. Exactly as it sounds. If you have very hairy legs and you are already fast, you can gain a significant amount of time over a 40K time trial. But if you don’t have much leg hair or you aren’t that fast, you won’t see nearly as much of a benefit. For middle-of-the-pack amateurs, it still comes down to doing it just because it’s something that cyclists do.

[hozn]

That is true, though in their video the lowest advantage (of the 7? samples) was still a whopping 50 seconds. Pretty amazing.

But yes, most roadies wouldn’t see much difference, esp since riding in a pack is not a 40k TT.

[mstone]

So, basically, the difference of catching one light over a commute? First World problems.

[hozn]

@mstone 94083 wrote:

So, basically, the difference of catching one light over a commute? First World problems.

I think one could apply that sentiment to every discussion on this forum

[jrenaut]

Most of the time when I ride, I’m absolutely positive that the wind resistance from the empty pannier that I have on in case I get a last minute grocery list is orders of magnitude above the wind resistance from my Chewbacca-grade leg hair.

[Dickie]

Shaving your legs as a commuter only makes sense if you like the way it feels or looks. I started shaving my legs during my racing days and have simply continued to do so, but I don’t expect any advantage from it. I have used the “massage” and “road rash” answers to explain my habit, but if I was to be honest it’s simply vanity and what feels good at this point. I once joked with my wife that I spend all year sculpting my legs, why would I then hide them beneath a carpet? The sad part is my legs were more likely sculpted by Picasso rather than Michelangelo.

[culimerc]

I call Bullsh33t!

https://www.youtube.com/watch?v=FkmCLOjk2h8

if a beard does not affect your time leghair wont either.

[scorchedearth]

Instead of shaving my legs, I wear sunsleeves. I wonder if it offers the same advantage.

[hozn]

Wind tunnel tests don’t always produce intuitive (or at least accessible) results. Beards are in front of the body, so maybe it makes little difference if that air is dirtier? Anyway, the test seems scientific enough for these purposes.

[MattAune]

@culimerc 94113 wrote:

I call Bullsh33t!

https://www.youtube.com/watch?v=FkmCLOjk2h8

if a beard does not affect your time leghair wont either.

The same crew that tested the beards has also tested leg hair. And they disagree with you. https://www.youtube.com/watch?v=DZnrE17Jg3I

Like Hozn says, the air that hits your face still has to go around your body. Having a beard that makes that air ‘dirtier’ doesn’t matter because it only gets worse as it hits your shoulders.

[Author]

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