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LA Can't Do It

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LA Can’t “Do It”


Why an Hour Record Attempt Might Not Happen


6/26/05 - Words and images by Kraig Willett


Despite the re-assurances of his current coach, and the empirical extrapolations of academia, I don’t think that LA can surpass the hour record held by Chris Boardman.  Not that it matters, though, since LA is hanging up his wheels in a few weeks…  What I’m about to present may seem like pretty tenuous evidence in support of a pretty bold claim (one that’s sure to draw the ire of a few people); however, relax folks, it’s just bike racin’ – and I’m just an abaqus-movin’-slide-rulin’-pencil-pushin’-not-much-smarter-than-a-box-of-rocks-dork!

Occasionally,  little nuggets of information from the pro bike racers get unintentionally released to the public.  Take, for example, the photos posted on LA’s coach’s website a few months back:

http://www.trainright.com/page.asp?page_id=content&page_content=gallery&cat=cycling&sub=TDF&gal=Wind%20Tunnel

That photo gallery linked above is one or two images short, though; as it seems that one or two images were removed from the page… But at least one of those images was not removed from the server (don’t blame me if the links below and above don’t work after this article is published!):

http://www.trainright.com/photogallery/images/Windtunnelday047.jpg

The image linked to above is but one piece of  evidence in support of why Ekimov seems to be so competitive in world class TT’s; it shows that he possesses exceptional aerodynamic qualities – in my opinion, that guy is gifted.

There are some other beauties in that gallery of LA in his aero position which confirm, for me anyways, that LA has no shortages in the power production department…  LA has always looked like a piece of plywood to me, but - hey man, whatever works!  Dude has won more Tours than anyone else – that says something, eh?

Now, I’ve tested quite a few elite athletes (and many weekend warriors) in the same wind tunnel as LA & co., so those monitors in the background on trainright.com are pretty familiar to me – they provide a bit of insight into LA’s aerodynamic resistance, and subsequently, just how fast he could theoretically go during an hour record attempt.  The number of interest is a four digit one (axial force in grams) in the upper left corner of the monitor in the background of this image:

http://www.trainright.com/photogallery/images/Windtunnelday006.jpg

I figure LA’s axial force in grams in his TT position is something like 2952 grams at ~30 mph.  That’s well in excess of 6lbs (at 30 mph), the supposed gold standard according to some aero guru’s.  Wanting confirmation of this guess (yeah, that image is a bit fuzzy, eh?), I conducted an unscientific poll on the BTR forum:

http://biketechreview.com/v-web/bulletin/bb/viewtopic.php?t=120

The takeaway from this poll was that the second digit in my original guess is debatable.  However, I am confident that the second number in my guess of 2952 is not a: “7”, “2”, “8”, “0”, or a “5”.  That leaves us with the possibility of it being a 1,3,4,6 or a 9.  The only number for the second digit that makes sense to me (after investigation of the linked Ekimov image above, and analyses of flat TT’s and hillclimb TT’s ) is the number 9.  So, in my opinion, LA creates approximately 2950 grams of drag at ~30 mph.  For those more comfortable with CxA (drag coefficient times frontal area) values (since overall axial force is a function of air density and relative wind speed), LA has a rather unspectacular CxA of ~0.266 m^2.  In comparison, I would estimate Ekimov (who is approximately the same mass/size of LA) to have a CxA of  ~0.232 m^2.  Whoa, that’s an approximate 13% difference!  No wonder Eki is competitive with LA in flat TT’s, but not the mountains!

OK, so I’m pretty confident that LA can produce lots of power to overcome his less than stellar TT aerodynamics when it counts (that’s why he wins, or is competitive in Tour TT’s, right?), but just exactly how much power can “the one” produce?

It’s best to estimate the supply side of the equation of motion (i.e, power generation) during a hill-climb TT – in this way, the unknown/variable effects of aerodynamics are minimized.  I took a look at last year’s Alpe d’huez TT to ballpark what LA can do for an hour long effort.  I modeled the course, took local atmospherics (which affect air density), and optimal pacing into consideration (which can also affect total elapsed time) and came up with the following estimates in terms of Watts per kilogram (W/kg)  for the top 20 of this stage during the 2004 Tour:

 

My estimates show that LA put out around 6.38 W/kg for this 40 minute effort.  This is pretty spectacular relative to his competition, and also compared to his effort just a few weeks prior during the Dauphine Libere during the Ventoux stage:

 

 

If we were to adjust his Alpe d’Huez time (where he timed his fitness just right) to an approximate hour long effort, I’d estimate that he would be capable of producing around 6.18 W/kg.  Assuming an Alpe d’Huez mass of 73kg that means that I’d estimate Lance would be capable of putting out approximately 452 watts for an hour at a mean elevation of 1250 meters.  All else being equal, this hand-waving-back-of-the-envelope-calcu-malation says that LA has a Watts per CxA ratio of ~ 452/0.266=1710 W/m^2.  For reference, this is a full 15%+ less than a similar technologically equipped Miguel Indurain during his record hour in 1994 (Padilla et al, 2000).

If these numbers are accurate, this means that in his current TT position at optimal fitness, LA would have had his lunch handed to him in a TT vs Indurain during his prime.

So, how about the “real man’s hour” record currently held by Chris Boardman?  In order to gain insight on this record, we have to know what Boardman’s/Merckx’s Watts per CxA ratio was (W/Cxa).  According to the same Padilla paper mentioned above, it has been estimated that Merckx had a W/CxA ratio of 1450 W/m^2.  That’s pretty good.  How does LA stack up?

Well, we have two pieces of information about LA’s non-aero bar TT position CxA.  The first is this image:

http://www.trainright.com/photogallery/images/Windtunnelday007.jpg

(again, don’t blame me if that link doesn’t work)

which is of LA on the hoods of his TT bike (i.e, aero wheels, helmet, frame, etc…) -> the axial force is 3708 grams at 30 mph.  This approximate 25% increase from his TT position is consistent with my experience measuring Cx and frontal areas of cyclists (don’t take my word for it, though, try it yourself!).  The other piece of information is that of the AMD info-mercial that was aired on OLN during the criterium dauphine libere a couple weeks ago.  In that spot, there is a shot of LA on his hour record bike (which might be UCI hour record illegal) – the axial force on the screen shows 3416 grams at 30 mph.  Well, this just isn’t consistent with neither my experience, nor the digital image overlays I created to compare the LA TT drops position to the AMD info-mercial position).

Knowing that the “truth” is somewhere between what has been communicated to the public in a marketing fashion, and what some skeptic like me has to say – we can safely estimate that LA  probably has axial force closer to 3708 g (or a CxA of 0.334) than 3416 g.  Let’s call it 3660 grams, or an even 0.33 CxA.  So, this would make LA’s W/CxA ratio in his prime fitness to be around 452/0.33 = 1370 W/m^2, which puts LA about 5% short of Merckx/Boardman’s values of ~ 1450 W/m^2.  If LA were to attempt the record at an elevation of 1250 meters, where the air density is lower, LA would still probably come up over 1000 meters short.

I’m convinced LA couldn’t have broken the hour unless he drastically changed his riding position in order to improve his aerodynamics.

Watch the Discovery Channel as they delve deep into the “Science of Lance Armstrong” on 6/27/05 at 8pm ET -> will the evidence they publicize support or refute the information laid out here?

Last Updated on Sunday, 23 May 2010 13:38  

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