Friday, November 27, 2009

Aero Brakes

I scrounged together some bits and pieces laying around the garage and came up with this for my turkey day project:

..somehow, I managed to get the improvised setup calibrated today, and made some #'s that were pretty crazy!

More pics and results here.

Whaddaya think?

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Saturday, October 17, 2009

Repeatability and the San Diego Wind Tunnel

A few years back, I wrote this sucker:

whoa, that's probably the third time I've used partial differentiation in a setting outside of academia!!! :-)

To be honest, my experience as a consumer product development engineer in the bike biz (2+ years) and the golf biz (coming up on 10 years now... holy cow!) is much more caveman based than what doing partial differentiation might suggest.

Granted, the tools/toys I get to play with in the golf biz these days are a couple steps above the beer cans and bits of string I got to use in the labs I had at my disposal while in the bike biz... ;-) ...but, still, I think that even with the fancy tools I get to use these days, I find myself relying on my caveman instincts when it comes to judging "goodness" of data that so many of the high tech gadgets can spit out.

Y'know, folks will have to assess for me how well their methodology and instrumentation they have used can repeat a given measurement/setup condition within a day and across days before it gets my attention. For example, with a pedaling rider in the tunnel, I have seen things (axial force) repeat to within less than 10 grams...but I've also seen things not repeat so well. Over the years, and more than a thousand runs with pedaling riders, I've grown to know how much I can trust what the tunnel is telling me...and that knowledge drives the way I choose to test.

The same kind of familiarity with repeatability is helpful when placing "equipment only" wind tunnel test #'s into context.

Not sure where I'm going with all of this, other than, I don't think folks think about experimental uncertainty enough - especially when it comes to doing field tests with a power meter. "Subjective validation" of these data might kick in if you wind up getting the answer you were more or less looking for:

Anyway, speaking of repeatability, I was checking out some additional repeat data I have on a specialized trispoke (the same one linked to in the partial derivative link above) today. I've tested this exact wheel/tire combination in a couple tunnels (texas a&m and I've tested the trispoke in the san diego wind tunnel eight times since 2005 (yeah, that would be over a four year time period) at a beta=0 flow condition.

What was the standard deviation of the multiple runs over that 4 year period for the exact same wheel/tire setup? 3.8 grams of axial force at 30mph. That seems pretty good to me. What do you think? What can the other tunnels do over that same four year time period in terms of "equipment only" repeatability?

So, yeah, that std deviation tells me about how well I can trust the data coming out of the facility here in San Diego over time. My caveman instincts are comfortable with these data out of San Diego! :-)

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Thursday, July 23, 2009

Amour de "Low"

I'm not sure how to spell "love" in french - it's Amor in spanish, and Amore in Italian, that much I'm sure of, and so, well, I reckon it's probably close to "amour" in french...

Anyway, after watching today's ITT in the tour, I'm pretty amazed at how much of the peloton is demonstrating behaviors symptomatic of the "disease of lowness". By that, I mean all the guys who wind up riding the tip of the saddle, only to shift themselves back on the saddle every 5 pedal strokes (I don't know what was more painful - how Contador felt during the ITT or how I felt while watching the DVR'd coverage a few minutes ago). The funny thing, for me, after seeing first hand how reach and drop interact in a wind tunnel with a wide cross section of athletes (from elites like Kristin Armstrong, Sarah Hammer, Phinney, Hincapie, Astarloza, Leipheimer, Popovych, Danielson, Marchante, Simoni, Millar, Sanchez, etc.. etc... to masters National champions like Ruth Clemence, or Alpenrose kilo record holders like BTR member Snigelmannen - way to take the record from Marty Nothstein! - to IM folks like Sindballe, Evans, Andersson, Fuhr, Ferguson, Major - to chubby, amateur, wannabe time trialists/IM'rs named Kraig) is that this disease has a cure...

The cure is simple, and it's called raising the bars in order to decrease the drop. huh? I mean, everyone knows that if you want to be aerodynamic, you have to have lots of drop, reach be damned, eh?

The favorite refrain from the "prophets of low" is: "move the saddle forward" or "get steep" isn't it:

Move the saddle forward and drop the bars "a little", or get "steep" is the magic elixir for the sickness of being too low, according to the pundits. Well, yeah, that seems like kind of an indirect way of solving the "bars are too low" issue, eh?

The fact of the matter is that from an aerodynamic perspective there exists a relationship between reach and drop for each individual, it's not an either/or deal...and despite what the interweb forums are full of, the UCI really isn't limiting things in the "forward" department based on my experience.

I'll use myself as an example of the "disease of lowness" - the last time I tested my TT/IM position in the wind tunnel was just a week or so after my IMAZ effort last november. During that test, I baselined my position, then looked at how reach and drop interacted. At three different bar heights, it became clear that if I "tipped it" (riding the nose of the saddle, rather than sitting on the saddle square), I was less aerodynamic than if I wasn't "tipping it"...and despite lowering the bars (more than "a little") the most aerodynamic overall position came at the highest bar height I was able to achieve - this bar height was probably a couple cm higher (or more) than the position I used for IMAZ.

These tunnel data suggest that if I were to take the advice of the "prophets of steep and low", (i.e - you just need to "move the saddle forward, and maybe drop the bars a little") well, I would be less aerodynamic and, therefore, slower. Thanks for the blanket, mantra-driven advice, but I think I'll pass, and let the beta/yaw equal to and not equal to zero data speak.

So, yeah, I can't really be bothered by all the "get low shenanigans" or "get low theatrics" the pro peloton seems to be brewing up these days. The wind tunnel here in san diego is the medicine that cured me of my own personal "disease of lowness". Keep in mind that I'm not alone with the uniqueness of how my reach/drop interact. Others demonstrate this same unique trade-off (some are listed above) of reach and drop from an aerodynamic perspective.

If one takes a "forest driven" rather than a "tree-driven" approach or process to TT setups, one just might realize that there exists a real opportunity to explore how much power one can produce (or wants to/chooses to produce in the case of IM) for the duration of their intended effort as a function of different reach/drop combinations.

I mean, if one can raise their bars, extend their effective reach, be more comfortable, be more powerful, and have the same (or better aerodynamics), well then, that sounds like a pretty good deal to me.

In the end, I'm pretty much enamored with "fast" and am not burdened by "the disease of lowness" anymore.

Kind of along these lines, I'm pretty sure LANCE demonstrated today, that once again, it's not about the's really about the floppy, un-aerodynamic jewelry hanging from your neck!!! ;-)

(and yeah, I think LANCE needs to raise his bars back to where they used to be four years ago... ;-) )

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Monday, May 4, 2009

Wheel CFD

I received a note from Jürgen, one of the principals of the website:

this morning. He gave me permission to host the pdf document that is distributed on his site that describes the work he and his crew have done with aero wheels:

I asked a lot of inane "cfd groupie" questions offline, ones that I hope he'll be able to shed some light on.

Anyway, I just thought that the work he was doing was cool and figured I'd point it out to folks.



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Saturday, May 2, 2009

crank it up

The big dawgs are lightin' it up in richmond right now:

that in-car shot of tony stewart's left rear quarter panel isn't too far off the fifty minutes of "rear quarter panels" I got a view of today during the Barrio Logan Grand Prix crit here in socal.

It was this race that put a severe crimp in my season last year... I got taken down late in the race and crashed pretty hard causing some bad things to happen to my rotator cuff. Anyway, I hadn't really planned on racing barrio logan this year, but since they finally added back the M35+ category, I had to support the local racing scene!

Well, I tailgunned it - but I really didn't have much of a choice - I haven't been going so well this year. If I had to put my finger on a single reason for the lack of power I've been seeing this year, I'd put that finger on all those long tempo rides I did last fall in preparation for ironman arizona. Regardless of the cause, though, I am just not pedaling the bike as well as I'd like to at this point. It'll turn around eventually, though, I reckon!

Anyway, it got kinda hard about 10 minutes into the race and that's when the race for 1st ended - six guys went up the road and 3 or 4 of them were sportin' Amgen jerseys. I think anthony galvan finally took it while continuing to sport his ibike power meter on the handlebars. nice!

it was pretty mellow in the back, and I went hard for the last few laps before coasting across the line with my sweet "2nd tier" field sprinting capabilities for a top 10 field finish. Much better than last weeks dana point debacle, where I had to pick myself up off the pavement with six or seven to go before snagging a top twenty.

I'm not sure I'll be doing the Dana Point race next year - too many doodz (master's racers nonetheless) willing to risk contact with steel barriers in pursuit of weekend "glory".

hey, I'm glad I got back on the barrio logan "horse" again, though - it's a cool race that's been around for quite some time. Eventually, the city will repave those roads, and boy that will make things a whole lot safer!

Before I left to go racing in old barrio logan this morning, I re-tested several tires on my rollers in the garage in order to determine their coefficient of rolling resistance. This time around I used my old-skool yellow wired powertap that I purchased used. As it turns out, things were pretty consistent with the SRM that I used last fall for similar testing.

I managed to take some pics of a couple of the "fancier" aero-featured tires - whoa, those weren't rotated like that originally!:

bontrager tire

zipp tire

the bontrager tire has a little "wing" as they call it that tries to fill in the gap between the tire sidewall and the outboard corner of the clincher rim (a mavic open pro is what my powertap is laced onto in the pics). That wing is claimed to improve aerodynamics, just as the dimples on the zipp tire are claimed to improve aerodynamics. Only the wind tunnel knows if these features are significant enough to rise above the "noise" of marketing wishful thinking, though, eh?

speaking of "noise" - let me tell you, those dimples make a heck of a lot of noise when ridden on 4.5" aluminum kreitler rollers. holy crap, not only were they noisy, but the high frequency vibration that I could feel through my chamois was pretty annoying as well! I wouldn't want to do a long roller session on these suckers.

I wonder how much those dimples cost on the supply side of things in addition to the demand side of things (the crr of the zipp @120 psi was only slightly worse than the veloflex @ 60 psi according to my quick experiment).

Interesting stuff!

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Saturday, April 4, 2009

Put 'em up!

This here's another wind tunnel shoot-out! ;-)

Tested a couple of fast wheels and a slew of fast tires (which just might make more of a difference than the wheel itself).

Standby for a heads up on how you can gain access to the same kind of results that manufacturers generate.

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Friday, March 27, 2009 World Champion Alums


That's just about all I can say about the most recent alum:

to post a world championship victory on their palmares!

I'm pretty impressed with Taylor Phinney's world championship ride and pretty much all of Team Phinney, to be honest - they run a tight ship! The guy is pretty "cool under pressure" too, if you ask me - I mean, think back to when you were 18 years old, and gave an acceptance speech like this:

to a group of strangers. I was in attendance during that ESA ceremony, and believe me, the video doesn't do his "presence" justice - to think that he's only 18 is pretty crazy.

Congrats Taylor, and the rest of team phinney!

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Friday, March 20, 2009

Thread #9

Back in 2004 prior to having any real rider positioning experience in the tunnel here in San Diego, thread #9 (we're at around 2500 threads these days) on the BTR forum dealt with the topic of elbow width.

Pretty interesting to read my perspective of 5 years ago - boy, that's an eye opener for me to be sure!! This stuff isn't always as "easy" as folks would like to make it seem.

Anyway, the images in BTR thread #9 didn't make it over during the site migration I did last year, but here's an interesting frontal area look at upper arm aerodynamics as mentioned in the BTR thread:

the numbers below the images are frontal area in m^2. All sorts of things are changing between images as I reached out, huh?! It would be interesting to see what might have happened if I had controlled for elbow width and hand elevation relative to my elbow when taking those pictures.

I reckon a vertical humerus would have turned out relatively worse than it did when I took those pics 5 years ago.

So, if you look at your position and you notice that you have a vertical or near vertical humerus/upper arm, you might want to consider tweaking your reach and drop in order to explore how things change with your upper arm geometry from an aerodynamic perspective.

Pics like I took back in 2004 can be insightful...but so can a full length mirror!


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Friday, March 13, 2009

Frame and Rider Aerodynamic Interaction

There was a thread over on the BTR forum a couple weeks ago that sparked my memory of a data set on the topic of frame and rider interaction.

So, I did a little internets digging, and finally found an online source of what I remember seeing.

(you might have to be signed in to google to access that link above, but check out page 34 and 35 if you'd like to verify for yourself)

In the mid 80's and early 90's, it seems, Chester Kyle did some tunnel tests at a couple different venues that looked at bike and bike+rider test runs. I think the idea was to gain insight into whether or not the floppy human pedaling on the bike made certain frames perform better or worse than when evaluated solo. There's not much background on the numbers I dug up out of the book entitled "High Tech Cycling" by Burke, so this could be a dog's breakfast published data set so to speak...

...but anyway, I made this plot based on what is publicly available:

so, what does everyone think is the frame(s) that, according to this data, are the least likely to exhibit appreciable frame/rider interaction?

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Saturday, February 28, 2009

Field Testing and Wind Tunnel Testing

Over the past several years, I've had the opportunity to do some wind tunnel testing with a variety of folks. On several occasions I've also had the opportunity to try and correlate the wind tunnel data to power meter based field tests.

Here's the field testing methodologies that I've tried in the past:

-flat, regression/Lim method
-indoor velodrome, caveman method
-dip/half-pipe chung method
-dip/half-pipe work per lap bootstrap method
-short laps-flat-ish work per lap bootstrap method
-long laps-flat-ish work per lap bootstrap method

It's been my experience with the data from the San Diego wind tunnel that the indoor velodrome has produced the best results when it comes to the academic exercise of matching wind tunnel data to indirect estimations of CxA based on power meter data. In windy conditons, it seems just a bit too easy to "post hoc adjust data" using stationary wind probes without high resolution data logging capabilities, in order to make things turn out the way one wants them to turn out.

The other methods (i.e, not indoor velodrome data) seem a bit cumbersome/time consuming and un-predictable/unrepeatable, in my experience (I had some pretty good calm Lim method data taken over many successive days that on average correlated very well with data, but this process took something like a week of early morning test sessions, IIRC - man, I don't have the patience for that ;-) ).

It's my current perception (which is, of course, subject to change based on new reliable information) that many folks who distribute information all over the internets are using math models, or field testing data reduction techniques, that don't quite capture exactly what is going on - which I feel can lead to inaccurate results from an aerodynamic body axis coordinate system perspective.

So, basically, just as I mentioned in this forum thread:

"often times, it's helpful to pursue multiple, independent lines of inquiry when attacking a problem. Field testing is but one way to gain insight, and hopefully, this methodology (referring to the work per lap bootstrap/chung approach) doesn't steer folks unknowingly down a wrong path. That would be a bummer!"

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Thursday, February 12, 2009

Fast Geometry Table Updated

I was asked to take a look at the Boardman geometry since it has a short headtube. By my math, the stack on that bike isn't too different than everything else out there. Anyway, it does seem to have some other things going for it as it climbs to the top using the same evaluation methodology as below.

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Saturday, February 7, 2009

Fast TT/Tri Geometry Part Two

Last time, I pretty much just documented what was available out there on the internets with respect to how different manufacturers make and sell bikes.

If the goal is to somehow take a stab at saying which manufacturer has "faster" geometry than another, well, one could simply take a look at the demand side of things. What's the demand side?

From a simplified perspective, the demand side on a flat TT course or triathlon venue pretty much boils down to total package aerodynamics (there are other variables such as weight, crr, mass, drivetrain losses, dark matter...). Now, I'm not able to say definitively one way or another how the frames themselves will behave in a wind tunnel, but this blogseries isn't about the's about the geometry they employ and the resulting way it forces folks to sit on bikes that is being evaluated.

The first way I chose to look at this whole deal was to simply say that I, as a rider, have a saddle height that I need to hit and a single stem that I'm going to put on all the frames out there. So I asked the dataset the question: "How would the resulting CxA I would have whilst sitting on these bikes, as measured in the tunnel turn out on average?"

Now, I understand that this might not be the best way to take on this challenge, but you'll have to give it to me that it's _one way_ to git 'r dun, eh? ;-)

So, the above is what I did... Along the way, I did some fancypants math to take the publicly available stack/reach values and transform them into the variables that I measure in the tunnel (I've got probably 1200+ data points at this time) and then run them through the stepwise, multiple, linear regression model I constructed that relates those measured position variables to CxA/aerodynamic resistance.

If the manufacturer offered a seatpost with an adjustable seat tube angle, I averaged the predicted CxA values from both ends of the STA spectrum.

Anyway here's how this method wound up ranking things:

So, what's everyone else think is a better way to do this sort of evaluation of TT/Tri bike geometry.

I'm happy to give your ideas a go when I get the chance!

Next time, we'll see how the recent trends of the manufacturers may have influenced performance at the world championships in Kona.

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Sunday, May 25, 2008

HED Interview

Cool Steve Hed interview over on Road magazine's site that I just ran across:

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Sunday, March 30, 2008

Perspective Shifting

Not more than 30 seconds (for me) after the finish of today’s SDSR Bonelli Park Circuit Race, I had a perspective shifting chat with a rider whom I respect, and at the end of the day, am a wee bit envious of.

His comment to me, as I was trying to catch my breath after giving it all I had in the finale, was simple and to the point:

“You might have gone faster yesterday if you hadn’t been looking at your

A simple comment, from a man of few words, yet, these words kind of felt a bit like they were cutting to the bone – I was taken aback a bit, to be honest - probably because I didn’t really recall focusing on the flashing SRM outside of the first 1k or so (and in fact, I am a proponent of taping the display over during timed efforts once one has settled in after the first few minutes of the effort – due to the distraction factor and the core belief that information can limit one’s potential on the day).

As I mentally re-evaluated yesterday’s hillclimb effort on the drive home after the race today, I came to the realization that this fellow I had the conversation with was more than likely correct in his commentary. I do distinctly recall looking at the SRM with 1k to go and about crapping my pants at how slow I was going. That knowledge probably did slow me down at the end of the day.
So yeah, yesterday, I simply had bad legs and knew I was in trouble in short order, and probably would have gone faster if I hadn’t looked at the SRM display. An extra 15watts would have come in handy too! :-)

The initial comment by this great rider, did however, allow me an opportunity to chat a bit about head position when racing against the clock. Based on my experience of testing over 100 folks in the wind tunnel here in San Diego, I can tell you that how one holds their head while going hard matters.

Yesterday, I kept the ol’ melon low on purpose (that whole concept of reducing CxA drives behavior even on hillclimbs..) , and I probably sighted 20 meters up the road at a given time – and maybe even looked straight down for big chunks of time – one can do that when you go as slow as I do! LOL!

So yeah, I can see how someone watching me during that effort up Glendora mountain yesterday might have the perspective that I was staring at my computer. The interesting thing was from my perspective, I was keeping my head in the right spot. Crazy how things can be viewed so differently, eh? Seeing a situation from someone else's perspective is difficult sometimes - I know I can improve in this area! :-)

Anyway, at around 6 m/s, sighting 20 meters down the road is like me looking 3-4 seconds up the road in order to take the best line through the switchbacks. How were my lines compared to last year? Well, since I raced this year and last year with the SRM and the same set of wheels, I checked it out. Turns out I covered 40 fewer meters this year compared to last year – but crap, I could have missed controlling tire pressure by a few psi and so that “computer distance” doesn’t really mean much, eh?

My global message, after talking a bit about head position, to this talented rider during our chat was simply, “sometimes it happens” – sometimes, despite what we really want to occur, life just gets in the way and as a result, our performance isn’t what we desired. It’s how one reacts, recovers and moves forward from those disappointments that holds some deeper meaning for me…

Today, I moved past yesterday’s disappointment, and rode well, nearly notching a top ten result on a day that the 100 rider field was whittled down to around 30-40 guys at the finish. Ya know, I’m not as powerful as a lot of the guys out there, but am reasonably competitive given the constraints the ol’ motor has. Most importantly, though, I have fun in the process of racing my bike.

FWIW, here’s a comparison of last year’s race (bottom trace) and this year’s race (top trace). This year was way faster, but somehow, I didn’t suffer quite as much… I guess being two kilos lighter helps when tryin’ to haul your ass up those hills, eh?

Keep moving forward, folks! :-)


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Wednesday, February 6, 2008

High Road

I might get into trouble with this, nah probably not, because it'll probably show up on some cycling news site pr piece here in awhile...

Anyway, during the wind tunnel testing we did yesterday, steve hed rolls in with his crew and some of the fellas from the "high road" squad.

Steve lent some insight with one of the last people testing of the day. Nice treat for those folks!

The above is a crappy cell phone shot of the team bikes.


Whose bike is this?


Saturday, January 19, 2008

LA World Cup

I took off a wee-bit early from work and carpooled up to Carson with Dave from in order to catch the second event on the schedule: the Women's Individual Pursuit! It was touch and go with the traffic we ran into... but we made it with a handful of minutes to spare

We got the hook-up on VIP passes from our buddy, Dr. Brent Kay from the Ouch! Medical Center in Murrieta - so that was nice! We first met Dr. Kay when he and Sarah Hammer tested at the tunnel a couple years ago. He goes real fast on a TT bike too - he smokes me every time at Fiesta Island!

Dave and I shook hands with lots of folks who had passed through the wind tunnel and old acquaintances of ours - it was pretty crazy actually seeing so many familiar faces at the track! Not only did I go up to this event to see some fast paced track racing action, we were there to show our support for a couple of really cool groups of people - Team Hammer, and Team Phinney.

Well, we cheered our hardest for Sarah during her Bronze medal winning pursuit effort where she layed down the fastest time of the event (you'll have to forgive the quality of the images - not much else I can do with my simple point and shoot camera)!

Nice work, Sarah!

Gold medal ride.

Silver medal ride.

After catching the women's pursuit we mosy'd our way down onto the infield, where it was also pretty cool to finally meet Connie Carpenter-Phinney! Kirk used to race against Davis Phinney back in the day (I did a few races with Davis, but I really can't call what I did "racing" - unless riding around for awhile before getting dropped by the Coors Light Train counts as "racing" ;-) ), and can remember watching the 84 olympics as a punk-kid where Connie took gold in the RR. Super-cool to finally meet her!

Here's some shots from Taylor's Gold Medal ride:

Passing the UCI inspection.

Getting ready to lay it down.

Layin' it down...

After layin' it down.

Awesome result for the current Jr. World TT champion!

All in all, a really fun evening that has inspired me to give track racing a go!

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Thursday, January 17, 2008

More Tunnel Pics

Here's a new picture of the Felt track bike that Sarah Hammer tested here in the San Diego Wind Tunnel:

Anyway, I'll be making the trek up to the Home Depot Center tomorrow evening to check out the pursuit finals and the rest of the action - if you see me wanderin' around, give me a shout!

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Monday, January 7, 2008


I had the opportunity to use Steve Hed and co's "humanipers" again recently. I don't think that's what he calls them - but that's what I'm calling them...

Humanipers - that's a combination of "human" and "calipers" - pretty clever, huh!? :-)

These things are pretty sweet - it makes measuring hip and shoulder width a snap in the wind tunnel. Steve gave/let me borrow these after he was done working with Levi last year.

The "humanipers" in action:

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Friday, December 7, 2007

Cycling Weekly (cont)

[cycling weekly] Do these principles differ according to the rider's strengths/body shape/riding style/event?

[kraig] The most important principle, IMHO, is understanding that positioning is a process that relies on the experienced use of the best measurement tools. Folks are pretty different in the positions they wind up with, but a good process will guide them along to the best result. If one focuses on the process the results will come.

[cycling weekly] In the case of each of the following, is it possible to say which is best and what sort of rider should use it? (a very stretched out position like the Superman, but within UCI limits. a Tuck position a la Landis and Leipheimer. A wide arms position like the UK Track team.)

[kraig]I don’t think it’s really possible to say which is best without testing it out. I’ve seen the Superman “work”, I’ve seen the Leipheimer position “work”.

[cycling weekly] Why do the UK Track guys ride with their arms so wide, do you think? Similarly what was so good about the Landis/Leipheimer position?

[kraig] I’m not sure why – I know that those guys test at a wind tunnel under the guidance of Chris Boardman (who is fond of telling Anthony McCrossen of that arm position doesn’t matter), so I’m sure they’ve got some evidence that suggests it’s the way to go. Maybe the ex-2006 Tour de France winner (I'm not quite sure how to phrase that - maybe I'll have to consult Floyd's legal team on that one??) just liked the way it felt for his hip – or he simply thought it was “cool” – or he had documented the supply side (power with his power tap) and the demand side (using the data from the tunnel here in san diego), and found that to be the best combination. Levi also uses power and wind tunnel data to guide his positioning decisions – it’s got to work on the road, though!

[cycling weekly] How important is it to get 'narrow' in the hands/elbows/shoulders/knees?

[kraig] People pedal differently, and this can affect the optimal position. I like to do sweeps on elbow width on pedaling riders under load (some facilities can't load up riders with any resistance, which is something to think about) in order to understand how axial force changes – narrower isn’t always better.

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Monday, November 26, 2007

Cycling Weekly e-Interview - part 1

A few months ago, I was sent a series of questions from Oliver Roberts of Cycling Weekly over in the UK.

I spent a wee-bit of time answering all of the questions he sent my way, and some of those answers made it into the final publication (which was cool to see!) - although, I had to purchase a digital copy of it to check out if I was quoted well! ;0)

Anyway, since I took the time to answer the questions for him - I reckon my answers would make for some good fodder here on kdublog - I've added some additional nuggets where I felt like it, FWIW!

here goes - question #1:

[cycling weekly] "The received wisdom is 'as low as possible is better' is this in fact the case?"

[kraig] I don’t think so.

I’m living proof that lower is not necessarily better. For the better part of 15 years of bike racing my TT setup was such that I made the bars as low as possible. Then, I went to the Wind Tunnel here in San Diego ( and explored what I call the "design space".

I quantified how much my axial force changed as a function of reach, drop, elbow width, forearm angle, saddle position, etc… over several different tunnel sessions. What I found out was that I had been riding below my potential in flat TT’s, largely in pursuit of becoming as "aerodynamic" as possible.

Last year (2006), I set lifetime personal bests at the 20k distance with a bar position that was 10+cm higher than previous positions - simply because I intelligently used the tools at my disposal to measure both axial force (I used a wind tunnel) and power production (I used an SRM Pro Power Meter). I also re-learned how to surf the pain curve during the actual time trials - that's worth quite a bit of time, I reckon!

Here's a photo comparison of my position in 2004 vs 2006:

Sure, going lower will generally make you more aerodynamic (that’s why folks tuck on descents!), but at what cost to the other parameter - power production? Going fast is a balance of one’s axial force, power production, and most importantly, putting it all together and executing via the supercomputer on race day.

Here’s an article I wrote that tries to send the message that using tools to help guide the positioning process is often times helpful:

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Sunday, October 14, 2007

Ironman Thoughts


I am totally intrigued by the whole ironman thing. I've gotten my feet wet in the scene, having done a couple half ironmans - all you google freaks out there can probably google my results and have a good laugh at how slow I am! LOL! :-) But, the difference between a half ironman and the real deal is like the difference between a half-pull and a full-pull -> fer all you non tractor-ites out there, this here is a full-pull:

Tractor Pull Full Pull - The best bloopers are a click away


Anyway, yeah, an ironman is just about like that - ya know, a bunch of Miller Lite drinkin' rabid fans hootin' and a hollerin' on the sidelines watchin' their favorites rip it up on Ali'i drive at 10pm, eh?

Seriously, though - whaddya reckon Macca's favorite brew of choice is? I reckon it ain't Miller Lite - or Foster's for that matter. But, damn, after a performance like that, you gotta believe that that fella was hoist'n his favorite after he ran his way into the top spot on the podium, eh?

Nice job, Macca!

I caught the first bit of the swim online on Saturday morning before goin' out on a nice ride with fellow BTR forum contributor, Neal for a nice ride down to the pacific ocean and back - thanks for the ride, Neal!

When I got back from that ride, Torbjorn had Lieto in his sights - just a matter of time before Sindballe overhauled Lieto, I reckoned. When I saw Torbjorn at interbike a few weeks ago, that dude looked like a completely different person compared to the last time I had seen him at the wind tunnel (

That's Torbjorn on the trainer outside the tunnel test section - bonus points if you can identify the guys to my right and left in the image above!

Yeah, so, Torbjorn looked really lean when we chatted with him at Interbike - this pretty much tipped me off to the idea that he was taking his running pretty damn seriously... Overall body mass is a pretty big contributor to running power, I reckon - I've modeled that in the past and body mass is definitely in Pareto's 20% of the variables that effect 80% of the results.

Torbjorn seems to be a smart guy - methodical in his approach, and diligent in his application of what he has learned to the task at hand. Got a problem with heat and running speed? Take a cue from the big guy Torbjorn - drop some kg's and figure out how to keep the core temp down. Nice, disciplined, pacing by Sindballe this year, eh? Damn straight - totally cool to see him grab a spot on the podium.

It also seems as if some of the ideas that the folks at Argon-18 have are producing better results on the run for the "Thunder-Bear" - Torbjorn. From what I recall during my chat with the folks at Argon-18 at Interbike this year, a major change in saddle position was implemented some time ago. They moved him backwards relative to the BB - and guess what, the big guy ran 2:57:XX at the big show.

Nice work fellas!

As a last little nugget, it's worthwhile to note that of the top 6 men's overall finishers at Kona this year, 4 of them have worked with the crew at

On the women's side, yours truly, has worked with one of the top three at

On a personal note, one of these days, I'd like to complete an iron-distance event - why? I think one learns a bunch about themselves when they are forced to test their limits. Whether it be during a 20 minute "au bloq" effort up couser canyon road, or an all day effort climbing the highest point in the lower 48:

so, get out there and run what you brung - you'll learn something about yourself along the way! :-)

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Sunday, September 23, 2007

Water Bottles and Speed.

Lots of triathlon debate about which method of bottle storage is "faster". Downtube, seattube, behind the saddle, between the aero bars - everyone's got an opinion...

I had a 5 minute discussion on the phone the other day with a manufacturer about how I would test this in the tunnel to determine the "fastest" method of storing bottles. I didn't get invited to the test session, which is cool (I've got a job and all and can't make it to everything down there! :-) ) - so, it'll be interesting to see how that test came out in the end.

Anyway, over the years, lots of confusion has been wrought on the general public regarding this topic thanks to inexact tools, inexact methodologies, inexact context, and, perhaps even hubris among other possibilities.

Let me just make my position clear on this topic - if determining how to store your bottles is your #1 goal in life, give me a call. With the use of a wind tunnel and a well thought out test protocol, we'll get the answer for your specific setup. However, don't expect to answer this question with a five minute set of runs - it'll take awhile to get a better answer for you.

Here's a cool video that we did at a year or so ago:


if that doesn't embed real well, check out this link (~1.4MB *.wmv file and right click/save as to view):

Go ahead and post this video, or link to this blog entry wherever you like - it'll help spread the word about the website and where BTR tests in the tunnel, and that's a good thing as far as making sure we're still around in the future! ;-)

take it easy out there,


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Saturday, September 22, 2007


There's a school of thought that suggests that if one focuses effort on the "process", the results will come. I've heard this, or lines of thought like this, for quite awhile - I read/listen to (I subscribe to, which I totally love as it allows me to "read" books while commuting to/from work...) lots of different books that have peripherally addressed this topic, so I'm not sure where I picked it up in the past.

However, recently, I read a couple books that really drove this "focus process development" point home once again. The first book that I hammered through in a couple days is "the four hour work week" - I didn't take everything to heart in that book, but there is some good stuff in there. In one of the sections of that 4 hour work week book, the author refers readers to some other business books - I latched onto "the e-myth" - and read that one. There's a great section in there that talks about process development being the goal of running a successfull business. I think there are many different applications of the "process development" concept - be it work, life, relationships whatever...

The combination of these two books, along with some other things clunkin' around in the ol' melon have given me some more things to think about in my typical non-linear, conceptual based caveman brain.

Simply put, I'm an achievement oriented kind of person, who thinks that the goal is pretty much "learning" - life experience is the best kind of learning IMHO. I've got to tinker, refine, learn along the way. The journey from "novice" to "expert" in any of my pursuits is a fun one full of great satisfaction for me...

What the heck does this philosophical crap have to do with bikes? Well, a few years back, I started learning about testing cyclists in wind tunnels - I focused on process development from day one and the results have been coming ever since then - not just for myself and my learning, but for those that I've met along the way as well - it really is just a big long journey where most folks benefit from the experience.

Results? Two out of the top five on GC at the tour de france this year have spent time with BTR and tweaking things. Now, today in the Vuelta - Samu just won the final TT and grabbed a spot on the final GC podium. More pics/discussion of the results of that Euskaltel tunnel test here.

I'm super proud of Samu, and the guys at Orbea who also seem to value the concept of focusing on the details of process development - and then reaping the rewards of that approach!

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Saturday, August 25, 2007

Zipp 808 vs TriSpoke

TJS of Minneapolis Minnesota writes about biketechreview's Zipp 808 vs Trispoke wind tunnel test on a public forum (thanks to the friends of BTR for pointing this one out!):

"I wouldn't mind the $15.00 if the test was done a little better. I feel cheated after buying it and don't recommend it for obvious (to those that have seen it) reasons. :(. "

Gotta love folks who complain about how the testing was conducted when 100% of the testing methodology was described in the publicly available, free to view blurb linked to above.


Despite TJS' interesting perceptions, I'm always open to feedback on what the best way to test the aerodynamic properties of wheels is (as a matter of fact, I modified the beta sweep for subsequent wind tunnel equipment tests I've conducted based on feedback from the BTR insider's list).

Anyhoo, let's hear your thoughts on how I should not "cheat" folks like TJS of Minneapolis Minnesota due to poor wind tunnel based wheel testing methodology.

I won't guarantee I'll use any of the ideas mentioned here, but I will guarantee I'll take them into consideration.

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