December 19, 2014 Login  


these newfangled aero helmets...
Last Post 04/22/2014 04:16 PM by Keith Jackson. 95 Replies.
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Keith Richards

Posts:759

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03/30/2014 10:42 AM
I was more making a point about helmet testing and how these types of tests don't account for real world use.

According to that test they extrapolated that one helmet was "faster" than the other during a five minute test of each helmet with the rider pedaling a fixed bike in a position that dare I say is probably unrideable by 95% of the cycling population. But yet these results will be put into a power point slide showing how huge a gap of five seconds is at 25mph.

Which brings us to why I think that Specialized ad is garbage. I know what that difference really looks like on a sheet of paper. Significant it is not.
----- It is his word versus ours. We like our word. We like where we stand and we like our credibility."--Lance Armstrong.
Oldfart

Posts:490

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03/30/2014 11:32 AM
All you guys saying helmets like the Air Attack are too hot. Have you tried one? I have one and can tell you that it is not hot. No more so than any hole filled helmet. One does not sweat because one wears a helmet. You sweat because you ride hard. Sweat management makes one helmet feel less hot. Loose the hair and you will feel less hot.
Keith Richards

Posts:759

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03/30/2014 11:48 AM
OF, it is not as if we have not worn different helmets over the years. The fact that Specialized sponsored riders were ditching their Evades for the climbing stages says it all.

And here is the thing, I am WAY more likely to be going slow up a hill in the sun than I am to be sprinting at 1000w wheel to wheel with someone. And that is going to inform my personal buying choice.

Now if I got seriously got into TTing would I get an aero helmet? I suppose so. But it would be far down on my list of "things to make Keith faster" in terms of performance.
----- It is his word versus ours. We like our word. We like where we stand and we like our credibility."--Lance Armstrong.
Cosmic Kid

Posts:1192

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03/30/2014 01:52 PM
@ Ride on - the fact that you use that old, tired canard is proof that you do not understand the concept. No one is saying wearing an aero lid means you win automatically. What people are saying is that it will make you faster, or conversely, allow you to save energy across the course of the entire race.. It is not just about the final sprint.

@ OC - there are a multitude of studies out there that show similar numbers to what I posted. And for re fence, there are a whole bunch of issues with how the MIt study was conducted....although I agree 100% directionally with their findings. IOW, aero helmets are one of the best, and cheapest, ways to improve your CdA.

@ Keith - so because you posted a pic of a admittedly flawed test (that position is ridiculous), that means that all wind tunnel tests are similarly flawed? C'mon man....you're smarter than that. And again, the test you reference is not even applicable because it is testing two similar helmets to find our which is "faster" for that rider. The magnitude of difference between an aero lid and a road lid is a lot more than 5w.

It seems that you are also playing both sides of the coin in your arguments - you dismiss WT results, but then hold up a wind tunnel test as an example of how the differences are minute. And if you can show me some data where a rider's bodies movement somehow negates the benefits of an aero lid, that would be great. Again, it is a mutually exclusive concept. The helmet does not cause a rider to move their body. They will do that no matter which helmet they use.....and an aero lid is faster either way (or saves you watts).
Just say "NO!" to WCP!!!!
Orange Crush

Posts:1251

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03/30/2014 02:09 PM
CK - where are those multitude of studies - links please.

Google search only brings up the MIT study.

Unless you can provide me with some hard evidence on the 20W claim (data and study setup), or some written discussion about what exactly was wrong with the MIT study, 5W is the only estimate I'd be willing to hang my hat (helmet) on based on what one can extrapolate from MIT study.
Ride On

Posts:454

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03/30/2014 02:12 PM
CK ... That was meant to be funny. Guess it missed the point.

No one here is saying that if there was an advantage they would pass it up. What people are saying is they don't believe it gives an advantage. So saying why would you pass up free speed is sort of falling on deaf ears.
Cosmic Kid

Posts:1192

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03/30/2014 02:18 PM
Yeah....all the scientific stuff is pretty hard to believe.

Let me flip the tables - show me the data that shows these helmets DON'T offer a significant advantage.

You guys must have power to spare or sumthin' if you can so willingly give up 10-20w.
Just say "NO!" to WCP!!!!
Orange Crush

Posts:1251

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03/30/2014 02:32 PM
I promise, if you can show my ANY hard data that I can actually gain 20W, I'll be the first to run...ehhr bike to the LBS and get one. I am due for a new lid anyways. But I have a feeling that I'm gonna be doing a lot of rides in my non-aero lid before I finally get that evidence. So far I've only heard mantras and I am not a religious guy.
Cosmic Kid

Posts:1192

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03/30/2014 02:48 PM
Go back to page 1 of this thread.....@ 0* a Specialized Evade helmet saves 20w over a Soecialized Prevail. I think it dropped to about 15w at 20*.

Please post a picture of the receipt. :
Just say "NO!" to WCP!!!!
Oldfart

Posts:490

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03/30/2014 03:01 PM
C'mon Keith. Since when are pros who we look to for tech advice? Pros used to ditch their helmets entirely when they were allowed to yet Giro test showed that heads were cooler with a helmet on because they made move across the scalp faster even at climbing speeds. Pro cyclists are sme of the most superstitious athletes with respect to equipment. How many riders pooh poohed indexing and integrated shifters and even clip less pedals when they first came. I'll trust my own feelings over some dumb athlete anyday.
Ride On

Posts:454

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03/30/2014 03:35 PM
There you go again, No I'm not willing to give up 10-20watts. What I am saying is I don't think a different lid is going to shave off 10-20watts. You have a better chance making this argument over on Slowtwitch than here.
Keith Richards

Posts:759

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03/30/2014 03:42 PM
Posted By Andy Eunson on 03/30/2014 03:01 PM
C'mon Keith. Since when are pros who we look to for tech advice?


You really just said that?
Posted By Cosmic Kid on 03/30/2014 01:52 PM
@ Keith - so because you posted a pic of a admittedly flawed test (that position is ridiculous), that means that all wind tunnel tests are similarly flawed? C'mon man....you're smarter than that. And again, the test you reference is not even applicable because it is testing two similar helmets to find our which is "faster" for that rider. The magnitude of difference between an aero lid and a road lid is a lot more than 5w.

It seems that you are also playing both sides of the coin in your arguments - you dismiss WT results, but then hold up a wind tunnel test as an example of how the differences are minute. And if you can show me some data where a rider's bodies movement somehow negates the benefits of an aero lid, that would be great. Again, it is a mutually exclusive concept. The helmet does not cause a rider to move their body. They will do that no matter which helmet they use.....and an aero lid is faster either way (or saves you watts).


Once again, I am not even talking about TT lids. That is not what this was originally about and I want to make sure we stay on topic. Like I said, I used it to point out how easy it is to make non-significant differences look like significant ones. In that TT example I posted a .001 coefficient improvement for 5 minutes is suddenly 5 seconds over 40k and the equivalent of someone finishing more than half a football field in front of you, which in bike racing land is cause for panic. Suddenly, an aero helmet is a necessity and the marketing man has you. The Specialized helmet Powerpoint slide is equally misleading as the differences in terms of drag coefficient are so minute that they are easily overcome by other more important aerodynamic factors.
----- It is his word versus ours. We like our word. We like where we stand and we like our credibility."--Lance Armstrong.
Orange Crush

Posts:1251

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03/30/2014 05:20 PM
Posted By Cosmic Kid on 03/30/2014 02:48 PM
Go back to page 1 of this thread.....@ 0* a Specialized Evade helmet saves 20w over a Soecialized Prevail. I think it dropped to about 15w at 20*.

Please post a picture of the receipt. :

Ha - I was expecting exactly that response. So the Spec marketing material is realistically all you have to back up the 20W claim

Not what I asked for. I don't believe claimed fuel mileage for cars either.
Cosmic Kid

Posts:1192

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03/30/2014 08:00 PM
@ OC:

"OK, show me some data"

*shown data*

"No, I don't like that data."

I can post umpteen white papers showing the aerodynamic advantage of aero helmets and you are just gonna say the same thing.

The data is there....I can't make you accept it.
Just say "NO!" to WCP!!!!
Cosmic Kid

Posts:1192

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03/30/2014 08:04 PM
@ Ride on - see response to OC.

But I'll ask you guys again - where is the data showing that there is no advantage to aero lids? I can at least give you guys data supporting my position of an advantage. Only seems fair to have you guys provide data backing up your positions.
Just say "NO!" to WCP!!!!
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