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-   -   What does a speed suit do? (https://www.bikeforums.net/general-cycling-discussion/1163571-what-does-speed-suit-do.html)

DrIsotope 01-06-19 07:41 PM

One of the colleges (if memory serves?) that was doing wind tunnel testing found 5-7W savings, shaved legs vs. non shaved legs.

Doge 01-06-19 07:45 PM


Originally Posted by jefnvk (Post 20735445)
OK, fair enough [MENTION=423651]Maelochs[/MENTION] and [MENTION=420341]OBoile[/MENTION], that makes sense what you are saying now. Yeah you are probably always going to be faster with it on than off in that exact situation.



I always thought the shaving was more to aid in medical attention to road rash, than actual aero affects?

Its both. I understand this is about TTs (racing) in the General forum, but that is what the OP asked about racing naked, and speed suits - ie being as fast as possible given the same (assumed) power. Keep hair out of the wind.

In the TT, places are often determined by seconds. Hair on legs slows you way down (could be several places) - even if covered the hair stick out and have some effect. Same with arms.
Then there is always the psychological thing. That is worth a whole bunch, but hard to quantify.


jefnvk 01-06-19 07:50 PM

Cool, I learn something new every day!

Maybe I just need a speed suit that covers my entire body. I should be able to get a good 15-20 watts, if the average person gets 5-7 :P

Doge 01-06-19 08:01 PM


Originally Posted by jefnvk (Post 20735470)
Cool, I learn something new every day!

Maybe I just need a speed suit that covers my entire body. I should be able to get a good 15-20 watts, if the average person gets 5-7 :P

There is cost in moving the material - ex covering knees.
That kit with the POC helmet in post #23 is the most aero junior has used, but someone is always testing in a tunnel something that does better.
The difference between different suits is a few seconds. The difference from them and a standard jersey is quite a bit. I guess at about 30 sec in 30 min for my kid. It depends on speed of course, but they do matter for rides against the clock.

Teamprovicycle 01-07-19 10:55 PM

So why is a speed suit faster than your skin?
, can the same result be had with really tight compression kit or is it some magical fabiric thing .

Ironfish653 01-08-19 06:57 PM


Originally Posted by Teamprovicycle (Post 20737391)
So why is a speed suit faster than your skin?
, can the same result be had with really tight compression kit or is it some magical fabiric thing .

Because the fabric surface can actually be smoother than skin as far as the air moving over it. Some suits are designed so with different types of fabric in different places and strategically placed seams to manage airflow.
Speed suits are also designed around the body positions and movements specific to cycling, while compression is designed to support the muscles, typically during high effort/impact activities.
Compression tights can be used as a stand-in for cycling tight, but they’re not padded, an being cut for standing up rather than the cycling posture, they ‘come up short ‘ in the back.
Also, compression garments come as top and bottom, which means that you have a waistband and a hem on the top, which is where a lot of the gains come from on a one-piece ‘speed’ suit.

Clipped_in 01-09-19 09:49 AM


Originally Posted by Maelochs (Post 20733369)
If you are fit, it makes you look fast.

if you are me, it makes you look even more ridiculous than regular cycling kit.

My wife and I saw a guy wearing a skin suit that should not have been wearing one during a casual ride up a local canyon last year. My wife had to go home and wash her eyes out with soap...:eek:

indyfabz 01-09-19 10:00 AM

https://images-na.ssl-images-amazon....4,203,200_.jpg

Makes good tires and maps and knows his restaurants.

Doge 01-09-19 03:34 PM


Originally Posted by Teamprovicycle (Post 20737391)
So why is a speed suit faster than your skin?
, can the same result be had with really tight compression kit or is it some magical fabiric thing .

Shaved bare skin is pretty fast. The dimples are supposed to disturb the air and remove the surface friction. I see a lot of debate here, mostly depends on surface.
Compression is also preferred,maybe so your core can relax.
Anyway, since naked racing is not allowed, I don't know there is a lot of test data on it.

For booties...
I *think* generally a covered shoo with shaved, oiled leg is better. It is cooler, and weighs less than a bootee.
That stuff is when looking for second/s.

burnthesheep 01-10-19 12:53 PM

In TT it matters more than the $3000 frameset.

My skinsuit was $89.

Worth a pile of watts at 28mph.

Some elite TT folks, yeah that $1000 could win your national TT title for you.

Doge 01-12-19 11:22 PM

At the elite level everyone has the stuff. There are little nuances that make a difference, but speed suits brand A vs brand B are too subtle to figure out which is more important.
It is generally power and position that create the win.

asgelle 01-13-19 08:12 AM


Originally Posted by Doge (Post 20745400)
At the elite level everyone has the stuff. There are little nuances that make a difference, but speed suits brand A vs brand B are too subtle to figure out which is more important.
It is generally power and position that create the win.

Nico Toutenhoofd did some wind tunnel testing with John Cobb and found differences of 8-16 W between skin suits. His writeup of the testing doesn't seem to be available anymore, but there is discussion of it with some reference to what it says in this thread, https://forum.slowtwitch.com/forum/S..._M_P2603335-3/ especially page 3. I believe a difference of 8W could be seen through virtual elevation testing.

Doge 01-13-19 09:11 AM


Originally Posted by asgelle (Post 20745667)
Nico Toutenhoofd did some wind tunnel testing with John Cobb and found differences of 8-16 W between skin suits. His writeup of the testing doesn't seem to be available anymore, but there is discussion of it with some reference to what it says in this thread, https://forum.slowtwitch.com/forum/S..._M_P2603335-3/ especially page 3. I believe a difference of 8W could be seen through virtual elevation testing.

I think in practice it is far less than that. There are many contributors to go faster than aero, and while the wind tunnel produces facts, there are alternative facts that may be more significant. There is heat dissipation, cut of suit, glove transition, yaw (one better at 0 yaw, another at 10 deg), material (can it be moved easily and weight, absorption) and comfort.

My kid is enjoying bringing cycling problems into his engineering classes at college. Based on an aerodynamics class, he's opened up his forearm position. They have 5 wind tunnels at school. Unfortunately all too high speed. But he does see that speed / yaw matters to what is optimal. I see this in the TT too. One suit may be better at 25mph and another at 35mph. I don't think it is a completely easy pick based on a tunnel test.

asgelle 01-13-19 09:16 AM


Originally Posted by Doge (Post 20745734)
... while the wind tunnel produces facts, there are alternative facts that may be more significant.

No there are not "alternative facts"; those would be lies . There may be additional facts, but that's something completely different. The results from Nico's wind tunnel testing provide data. They can be used intelligently or not. They can be supplemented usefully or not.

asgelle 01-13-19 09:22 AM

[QUOTE=Doge;20745734 I don't think it is a completely easy pick based on a tunnel test.[/QUOTE]
I'd say it isn't easy based on someone else's test. For the individual in the wind tunnel (with a good team running the tests), I think the results would be pretty conclusive. In any event, I was just pointing out that in contrast to what you wrote, the differences between suits can be determined and may be significant to many competitors

Doge 01-13-19 10:22 AM


Originally Posted by asgelle (Post 20745742)
No there are not "alternative facts"; those would be lies . There may be additional facts, but that's something completely different. The results from Nico's wind tunnel testing provide data. They can be used intelligently or not. They can be supplemented usefully or not.

There are many facts not being considered by a wind tunnel test - those are not lies, rather alternatives to how racing really is vs a lab.
I believe the data, I just think it is a smaller part to going fast than most believe. As in many lab test, the results are data points, and facts. But they may not correlate to a rider going faster.

One of the discussion points to the thread you linked to was inflate Tufo tyres hard. Yup - because Tufos have hard casings, yet we see many tests on tyres that show lower pressure is better. So what should be done really depends on a lot of other things. The person that just goes with the lab data may be mis-directed.

Most the high end stuff, including speed suits have areas they work better than others.

Doge 01-13-19 05:01 PM

This is a link to someone that went from 191W to hold 40K to 181W. I find this much more believable. ~4% over changing lots of things. Shoot 1% is worth a lot, but look at the things that changed and what the lab test said the effect was - at 0 yaw. If in any of these there was more discomfort, or handling was decreased, I expect real life application would be different. And then real wind and real pavement make things different.

I see few riders that do not turn their heads and negate a lot of the aero benefits of their helmets, which is why a less aero helmet like the KASK Bambino, or a POC may yield faster times than a more aero one.

In the wind tunnel with the Ventum One ? Cody Beals

Maelochs 01-15-19 12:58 AM

I second Doge here. Most wind-tunnel tests involve holding an optimized position and further optimizing it.

In a real TT, the rider hits bumps, turns corners, hits side-winds, and moves his whole body and head. The gains which add up over a 40K test might be much smaller over an actual 40 K race.

As he notes, a lot of folks have moved away from the really long-tailed aero helmet because while it provides a tiny benefit when perfectly oriented, it provides excellent braking in any other orientation.

not saying don't do all the testing and don't buy all the gear. Half-a-percent can be the winning margin. And even if you don't race, buy what brings satisfaction, regardless of the numbers. But ... it is useful to know which numbers apply and how much, in the real world---unless you are a pro wind-tunnel test-rider.

downhillmaster 01-15-19 05:26 AM


Originally Posted by Teamprovicycle (Post 20733188)
To a amature racer skin/speed suits seem kinda silly .
spend almost 1000 bucks to cover up in a thin silly material.
why not just race naked , or shorts only .:foo:

I don’t know much about speed suits but have you ever thought about using HotHands to keep your hands and/or feet warm?

Doge 01-15-19 09:41 AM

Maybe fits...start at 3:14 @4:50 he brings up the point I did a ways back. That the most aero may not be the fastest as you give up comfort/cooling etc. So picking off a list from lab tests also requires that you know the "other" factors. Comfort and heat/cooling being huge ones.

Maelochs 01-15-19 11:29 AM


Originally Posted by downhillmaster (Post 20748628)

I don’t know much about speed suits but have you ever thought about using HotHands to keep your hands and/or feet warm?

How do HotHands fare in wind-tunnel testing?

Rollfast 01-15-19 11:50 AM

Wind tunnels are kinda cold, aren't they?

Maelochs 01-15-19 12:28 PM


Originally Posted by Rollfast (Post 20749202)
Wind tunnels are kinda cold, aren't they?

Well, they are windy,.

burnthesheep 01-15-19 01:41 PM

After reading some of the responses here it seems the sentiment among some that amateurs need not use fancy “pro” equipment.

One of the most interesting and important holders, twice, of the hour record.....was an amateur. Graeme Obree.

Frequently ridiculed for unorthodox decisions.

Recently proven to have achieved the lowest CdA drag hour record.

Yes, some amateurs can TT or pursuit pretty fast.

Pros TT over 30mph at near 32 to 33.

I’ve never seen a local C group rider in a skinsuit. I’ve only seen mine in person and the ones used at the Charlotte speedway TT.

At that there were about 100 folks. The fat part of the bell curve on speed was about 21mph. I went 25.5mph and finished upper 1/4. Course record is 29.x mph for a tenner.

Work harder and you can go fast too instead of bemoaning other people’s equipment choices.

Koyote 01-15-19 01:43 PM

So, how much faster would this guy be if he shaved off the 'stache?

https://cimg3.ibsrv.net/gimg/bikefor...4d979777f1.jpg


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