Do you understand the meaning of the word "marginal?"

Yes I do, do you think time differences of a couple of hundredths of a second count as marginal? Because that's what can seperate winners and losers in this event. You may think it's marginal, but I'm telling you from experience once you impact your ability to recover even a slight, or 'marginal', bit you impact your ability to put out big watts on the front when it's your turn to pull.

"Since aerodynamic drag has such a huge impact on performance, our approach to position optimisation has revolved around refinements to hand, forearm and elbow positions. These small changes to arm positioning have allowed greater comfort without a cost to Bridie’s coefficient of drag (CdA). The goal here has been to optimise the consistency of her position to allow an improvement in her ability to maintain the position for the full 60 minutes."

This is fascinating but also a total tease since they don't provide any description or photos of how they tweaked hand, forearm, and elbow positions.

Right, but as you yourself pointed out, there's more to team pursuit than rider CdA. It's critically important to ride tight. It's critically important to make crisp exchanges. It's important for all riders, while in front, to be in a position where they comfortably generate 600+W.

From this thread we've established that wide-arms can be quite aero.

My point here is simply that if the teams find that the difference in aero between narrow and wide is marginal...e.g. something on the order of 1-5W at speed, then they might decide that all the other stuff - bike handling, power, might the decision might swing to wider. This shouldn't be a crazy, controversial statement. It's not dismissing the important of aerodynamics. It's simply viewing the optimization of team pursuit performance as a system optimization problem. Not an aerodynamics optimization problem.

Either that or all the team running wide arms have either found that to be most aero. In which case we have to wonder why so few IP riders do the same.

Or they're just dumb.

Edit: This is really just re-stating what Titanflexer said early in the thread. Only he didn't have the balls to threaten the ST church-of-aero by pointing out that those decisions involve marginally discounting the importance of rider CdA. :)

Yes - a tease! But cervelo has tweeted some pics of their work with her. Her hour record attempt is scheduled for tomorrow - streaming live video here: http://cyclingtips.com/...ls-uci-hour-attempt/

Since she is a national caliber time trialist, I am sure it would be easy to find pics of her time trial position to compare changes.

This. I have tested around 2 dozen hand and arm combinations so I know what's fastest for me. My team mates, who have tested as much as myself, found their own fastest hand and arm positions which are different from mine. Test, test, and test again,

For me position vs power has always been a very real tradeoff. At my last fit I came up a skosh but front but was able to gain 20-30 watts in power production because I had a position that was actually comfortable to ride in. One of the other suggestions at the time (which I haven't yet tried) was to go wider so that I can actually breathe (turns out that's kind of important). As with all of this, there is likely a balance to be found between what is fast and what is sustainable for the individual...

As said in some posts below. Arms in line with quads. is most aero. Any narrower can lead to merely presenting more frontal area.

IM people who have their arms to close together all the time end up with discomfort on the outside of the deltoids. It can be okay for shorter course athletes comfort wise, but then it may still be less aero.

Birdie's position on her way to smashing women's hour record:

http://cyclingtips.com/...h-46-882-kilometres/


https://mobile.twitter.com/...0472890354024448?p=v

https://mobile.twitter.com/...006349021184/photo/1

Sorry about posting links instead of actual pics

I am failing to see the advantage in racing/riding of front wheel visibility. if wider folks are tossing a bta set up in there, where is the visibility and what advantages are lost. I don't need to see precisely when I am "not" hitting a pothole and can ride a line better by focusing a bit further up the road(like driving)

I have had some folks thinking that they were going to save me a ton of drag by going wider as I am way narrower than hips/legs/quads. results always say differently for me. maybe my def. of narrow is different than others, as my arms touch from hands to elbows. opening up even 2cm adds drag for me and it stays fairly consistent out to 15cm gap(which some here might still consider narrow) a buddy decided to emulate that with same results. I feel extremely stable like that as well and have no breathing difficulties even with a 42" chest at 5-9. no clue on how it would feel on track at 30mph as I have not tried that but have done a few 2,4-person tts like this with no issue. just touching a few of the points mentioned in this thread

I've fiddled with wide arms as well. It's not a huge drag penalty for me, about 5w compared to arms *very* close, and I could see making up that time difference and then some on even a mildly technical or rough course. However, the thing I can't figure out is how to handle hydration. I'd really rather not have a bottle on my DT.

Absolutely true! All that you just said...

---

AndyF
bike geek

When you're a hammer, everything looks like a nail. :)

I fixed the first one. Sorry about that. The one you re-quoted is up to you....

It seems that putting your arms together from hands to elbows reduces the surface area of your arms subject to drag. This is good information. How much drag is added when you open up to 2cm?

Going very narrow for me was *huge*. I became instantly, measurably faster. Though I have a narrow shoulder and hips ( for a 6'3" 175 dude). So that makes some intuitive sense.

So I keep my 40K position for track IP and TP. Or as close to it as I can get given #$^^%# track bike geometry.

For an experienced IP/TP rider, front wheel visibility is, I think, a non-factor. You "just know" the tolerances. When you're cutting downtrack at 35MPH to drop in line you don't have time to "look" at wheels.

I haven't found bike-handling to be an issue. (despite my theorizing in this thread). But I'm not an elite-grade TPer.

Semi-narrow elbows (somewhat narrower than shoulder width), hands next to each other for a tapering V forearm position, but separate rather than overlapping, presumably for bike handling purposes, forearms angled slightly up, this is precisely what I'd have expected.

Andy's comment was in regards to team pursuit setup, where riders have no brakes and want to draft as closely as possible.

my position does not preclude that. narrow wrists make a nice opening to see through

My own personal experience with this is that wider elbows allow me to push my chest deeper down and still breathe well. The elbows may stick out a bit more, but the lower head and torso might more than make up for it.

---

----------------------------------------------------------
Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com

Well for team pursuit at least, front wheel visibility is important.

---

AndyF
bike geek

I am experimenting with wider elbows, I feel it allows my head to drop. Previously my elbows were "slammed" together.

Will be checking it A2 in a couple months.

---

Ironman Certified Coach

Currently accepting limited number of new athletes

I have a SC 9.9 with the Bontrager one piece base bar. The arm rest are mounted on the bar. The only way I could put them wider was if I placed the arm rest on the outside of the arm rest rather than the traditional inside of the arm rest. Has anyone done this with their SC and if so can you report if it worked. I think that couple of inches my arms would be wider would assist in the comfort area.

---

Barry Dmitruk
2017: Florida 70.3 (done); Mont Tremblant 70.3 & Ironman