There are lots of very clever people out there that can estimate this stuff.

They had data from Faris. They know or guess Stadlers CDA. They know this riding time, road conditions, temperature etc. It would be pretty accurate. We all get shocked by 335 but for a pro that is an outstanding cyclist it's not unreasonable. The TDF guys do long hard training rides with an average over 300. That's in training.

I know that it can be estimated knowing the CDA, but generally when doing this it is best to do it on a CALM day with the wind. Last year at Kona does not qualify as a Calm day.

I would be interested in hearing smartin or the Big Cheese comment on this.

Maybe we could crosspost this on bike tech review and see what they think about estimating wattage from a known CDA on what amounted to one of the windiest days in the history of the race.

I got a powertap 5 months ago, and have done nearly all my hard interval sessions and testing on the hoods. This has increased my CP60 substantially to about 250W, but how much power would you expect to lose by dropping onto the aerobars.

Yesterday I did a 56m flat 1/2 IM test @ 188W, which seemed about right, at least the run was OK. That would be a drop of about 30W from the hood calculation. More or less right?

Obviously I gained a lot from being more aero.

That will depend on your bike fit and what % of your training time is spent in the aerobars.

In isolation what you say is true. Without the watts benchmark Faris set in the same conditions it would be pure guess work. If you have 2 test subjects that ride in the same conditions at the same time and you have the CDA and watts from subject (A) you can estimate the watts of (B) based on his CDA and riding time. Not that hard to do.

You should not lose any amount of power if you train correctly. You will lose some power at first, but that is just because you are using new muscles and using muscles differently. If you spend the vast majority (90%+) of your time training on your tribike and spend most of that time in your aerobars, your body will adapt to generate power in that position. If your fit is right, it is only a matter of adapting to the position.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Still seems like there would be too many confounding variables over a long day in extreme conditions.

Strangely enough, I can feed me. However, unlikely it may seem I am not fluent in Danish, given that there are only 5.5 millions Danes I would not think I am in the minority either. If you mean that I should have put it through Google and have an automated translation I would think the thread from Normann's site would have explained why not.

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"How bad can it be?" - SimpleS

Can't really compare power in a maximal effort (like a TT or hard interval) to power in a controlled, paced submaximal effort. I don't really care if my max sustained ("FT" or "CP60") power is higher or lower between positions. All I care about is how much power I can hold at race effort. In a half or full IM, we're holding back power anyway, so who really cares if the position "costs" power at max effort?

Remember -- power isn't "free." If a given bike position allows us to generate more power, and we do so, we will pay for that power on the run. We still need to dose our power out carefully.

When you say, "a drop of 30W from the hoods," do you mean that you can ride 56 miles at 218 watts on the hoods, and 56 miles at 188 watts in the aerobars, and run exactly the same? I doubt it -- but if it's true, it tells you that you need to spend more time in the aerobars. Your power should be very much the same between the two.

230W has gotten me right around or a bit under 24mph in flat ~20mile du/tri bike legs, and I'm 6', 170.

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"Go yell at an M&M"

Don't I remember that someone on the wattage list was able to hit 40kph for an hour with 200W?

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"Go yell at an M&M"

Ken what is your handlebar drop? I think Ashburn is ~21 cm and your stats have a slightly better ratio of speed to wattage.

"Don't I remember that someone on the wattage list was able to hit 40kph for an hour with 200W?"

It may have been me...but there's no way I'm running after doing a TT in that postion.....

40kph takes me about 190-195W or so in the full aero get-up...but I'm also 1.75m and 61kgs or so.

What happened to your other leg? 61kg, sheesh...

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"Go yell at an M&M"

funny!

I think complete lack of upper body seems to equal low CDA!

215 watts at 40kph is the best claim I've heard from a real person under real conditions so far (except for roady above -- that's pretty good!).

RE: 2:15 is at least 250 watts -- sure, one can do better, but that's a pretty safe bet unless we're dealing with some of the more obsessive types. Like, uh, Ken. ;-)

FWIW -- I've done 8k at 24.8 mph and 251 watts (that being the longest I have ever been able to hold 251 watts). Indicative of an actual race was 22.5 mph at 199 watts in an oly race (with 3 u-turns and some stop signs to roll through; no disc), and 20.3 mph on 147 watts on the first loop at Caliman (smooth roads and light breeze; with disc).

These aren't stellar results, but they're at least in the right direction.

Some of my real numbers from real races. Each of these is a flat course.

20 miles (2 loops, somewhat windy): 229/23.2 (2005), 230/23.5 (2004)

20 miles (little wind): 232/23.9 (2005), 238/24.4 (2004)

16.4 miles (headwind back): 229/23.2 (2005), 245/23.3 (2004)

2005 was a bit lower front than 2004.

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"Go yell at an M&M"

How low is that?

[reply][quote]
2005 was a bit lower front than 2004.
[/quote]
How low is that?[/reply]

Between 1" and 2", I think.

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"Go yell at an M&M"

"When you say, "a drop of 30W from the hoods," do you mean that you can ride 56 miles at 218 watts on the hoods, and 56 miles at 188 watts in the aerobars, and run exactly the same? "

Not exactly, I'm comparing 1/2 IM power on aerobars, which I experienced in a race simulation on Saturday (188W), to 1/2 IM power estimated, from my tests when riding on the hoods, using the above calculation (1/2 IM watts should be 80-90% of FT( 255 x 85/100 = 217W)).

There's a difference of 29W and I wondered if it was to be expected. People seem to be saying there should be no difference in power produced in the 2 positions. In which case I guess I should be training a lot more on the aerobars.

Thanks

   

That's quite remarkable. I've never actually tried to keep it at 40kph. But, back-calculating from my races, it looks like it would take me ~213 watts to go 40kph. To do it at 190 watts would require a CdA of about .19, which strains credulity, unless your name is Kirk.



--jens

'To do it at 190 watts would require a CdA of about .19, which strains credulity, unless your name is Kirk.'


yeah, bear in mind though that I'm not much bigger than he is! A little taller, but much more narrow. Looking at TT data from 5 different flat 10-15 mile TT's,and one flat (windy) 40K, 265W gets me about 27.9 or so, averaged over all 5. With crr @ .43 (damned tubular), that puts me, I guess, around .19.

The frustrating part is that my 20 min power is over 300W, but I've lost about 10% in the new TT position. If it ever comes back, I may actually be fast!