# Article: Big Fat Helmet (tm) by Kraig Willett



## gregg (Oct 30, 2000)

<b>Big Fat Helmet™</b>
7/19/04
Words and images by Kraig Willett

Can someone please tell Robbie McEwen to retire the Big Fat Helmet™ that he and his teammates wore during the opening Tour de France prologue? It is physically painful for me to look at that thing. Not only is his helmet just plain dorky looking, there isn’t a doubt in my mind that it is an extremely slow helmet and ultimately is a detriment to his time-trial performance. What would make me say such a thing?

Well, I was recently lucky enough to spend some time in the <a href="https://www.alliedaerospace.com/WT%20Facility.htm">Allied Aerospace</a> wind tunnel where I got to tunnel test some one-piece aero bars. During that entry I also got to stick my long-legged and gangly self in the test section and quantify my aerodynamic properties. 

<img src="https://gallery.roadbikereview.com/data/roadbike/511/102713figure1.jpg" width="276" height="384">

As part of my aerodynamic positioning analysis, I took the time to verify that my tunnel results were reflective of real-world results. I did this by conducting a field-test using a power meter, an anemometer (wind speed measurement device), and a known piece of roadway.

As one should expect, the “real-world” test showed that my tunnel numbers and field numbers were in agreement to within a few percent. As a final step in documenting my current position, I also measured my frontal area using a makeshift photo-studio in my living room. The image below illustrates the importance of making sure your pets - in this case my dog Lucho (named after the late 80’s Columbian climber <a href="https://www.nuestracolombia.org.co/m_englishversion/madecolombia.htm#LUIS%20(LUCHO)%20HERRERA">Luis Herrera</a>) – are kept confined. This confinement, of course, is necessary in the name of science…

<img src="https://gallery.roadbikereview.com/data/roadbike/511/102713figure2.jpg" width="213" height="351">

Thanks to the miracle of a modern digital photo manipulation software package, it was possible to remove Lucho and my bicycle from the original photos in an effort to improve consistency in the results. What was left, then, was a bunch of black and white pixels that could be counted in order to determine a frontal area measurement (hint: the inclusion of a known reference area - that black piece of construction paper hanging on the ruler to the left – is what allows for the final correlation of pixels to square meters). The images below shows some examples: my standard TT position with three separate helmet configurations.

<img src="https://gallery.roadbikereview.com/data/roadbike/511/102713figure3.jpg" width="359" height="491">

When this exercise was all said and done, the frontal area analysis for the middle image above (my standard position and aero helmet) correlated well with tunnel measurements using some standard assumptions defined in the scientific literature with regards to my body shape. After my position investigation was finished, I had convinced myself that measuring frontal area was meaningful.

Back to the helmet thing, though: the black and white images above should show that the conventional Giro helmet presents a slightly larger frontal area (as the distinct bulge between my shoulders shows in the right-most image above). I would speculate that the head fairings that pro’s in Europe used last year did not significantly increase the frontal area of a well-positioned rider. Furthermore, the streamlined nature of those fairings should have improved rider performance due to the more aerodynamically slippery shape that resulted.

With new safety standards for TT helmets in place this year, helmets necessarily got bigger in frontal area. From the looks of it, they are nearly as big as a standard helmet, but are, for the most part, more streamlined. If one makes the precarious assumption that the only thing that changed in the aerodynamic properties of the helmets from last year to this year was the frontal area, we should be able to ballpark just how much slower these new “safe” helmets are during a 40k TT.

The following table shows the results for the three helmet configurations I took data on:

<img src="https://gallery.roadbikereview.com/data/roadbike/511/102713table1.jpg" width="440" height="131">

Based on a frontal area analysis, it is reasonable to estimate that the wrong aero helmet can impact TT performance by around 20 seconds or so. In Robbie McEwen’s case, though, I think the penalty is much greater:

<img src="https://gallery.roadbikereview.com/data/roadbike/511/102713figure4.jpg" width="393" height="228">

…and the updated table:

<img src="https://gallery.roadbikereview.com/data/roadbike/511/102713table2.jpg" width="535" height="136">


So, who is going to tell Robbie the bad news about his Big Fat Helmet™ – you, or me?

_______________________

Kraig Willett is a product development engineer in the golf industry, a former Category 1 cyclist, and owns/operates his own company: K-dub Enterprises. K-dub Enterprises is the home of: BikeTech Review (<a href="https://www.biketechreview.com">www.biketechreview.com</a>), which provides objective laboratory based bicycle product reviews and The Count, which generates product usage statistics during selected cycling events. Kraig can be reached via email at <a href="mailto:[email protected]">[email protected]</a> or by phone at (760) 723-5839.


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## HouseMoney (Oct 28, 2002)

The August 16th VeloNews has a little blurb, with photo of Robbie in the Lotto helmet. They noted the resemblance to Rick Moranis in the movie "Space Balls"!

One of the tour teams had a helmet that from a frontal view looked like they all were wearing watermelons on their heads. I forget which team it was. I'll have to check out the final ITT to see if they're still wearing them.

What's up with the chihuahua?


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## asmith (Jun 26, 2004)

Great article!


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## Live Steam (Feb 4, 2004)

I still think he looks like The Great Kazoo :O) Man I can't find the original cartoon image, but here's one from the movie.


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## ClarkGriswold (Jun 15, 2004)

*Picture Please???*

I've tried and tried to find a picture of McEwen's TT helmet, but can't? anyone have a shot of it? Thanks!


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## rroselli (Jan 2, 2003)

*Nice job Gregg...*

I can only imagine the science Armstrong's cast and crew must get presented with. What about the riding jersey Postal wears? What are the differences there? Materials, fit and so forth compared to other contenders? And comparing that to what we might get off the rack or online?


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## njmtbbg (Aug 19, 2003)

*I tried to upload the photo but...*



ClarkGriswold said:


> I've tried and tried to find a picture of McEwen's TT helmet, but can't? anyone have a shot of it? Thanks!



the image is too big.

(Get it?)

B.


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## HouseMoney (Oct 28, 2002)

Live Steam said:


> I still think he looks like The Great Kazoo :O)


Nah! Closer to Lord Dark Helmet.


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## spankdoggie (Feb 13, 2004)

Whatever. If none of you nerds can post an actual photo of the helmet in question, then let this stupid thread drop to the bottom.

Nerds.


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## Live Steam (Feb 4, 2004)

I searched and can't find it. Maybe they're embarrassed of it.


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## spankdoggie (Feb 13, 2004)

Actually I think I saw it on OLN today. Funny looking.


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## FatSlowGuy (Jul 17, 2004)

Oh wait! I have one.....I was using it as a chamber pot.


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## Francis Cebedo (Aug 1, 2001)

This is Robbie McEwen in the final long time trial. I kid you not!!

He said "F that stupid helmet. I'm not looking like a chump so that those roadbikereview fools can make fun of me. Good thing I had all those prologue photos destroyed!!"

<img src="https://www.cyclingnews.com/photos/2004/tour04/stage19/s19DSC_0199mcewenfocus.jpg">


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