Hmmm. I understand what youa re trying to say here. But I'm not buying that a bike frame is worth 21watts over 3km. something tells me that there is more going on here than meets the eye. Not to mention this woudl throw the whole aero helmet industry out the window ;-)

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This is your life, and it's ending one minute at a time. - Fight Club
Industry Brat.

Theres a lot of variables at play. Any chance you'll do a test to isolate frame differences?

I'm guessing those are VF Records in pic #1 so it's not like the switch to clinchers would be a huge savings.

I can't imagine the frame alone would be worth 20 watts at an effective 0-2.5 degree yaw that a track would produce.

Maybe it's the clinchers.

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

maybe it's all about the clinchers?


Quake

It could be the wheelset more than anything? Or perhaps less wind on scond run. To many variables.

Although it doesn't look like it I assume that's the same rider in both shots?

It's the dimples, right? No aero helmet, no shoe covers, but the same time, hmmm.

Of course, it would have been really interesting if you could have gotten the riders to switch bikes and repeat (assuming appropriate setup adjustments).

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Behold the turtle! He makes progess only when he sticks his neck out. (James Bryant Conant)
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Looks like you've got a couple more "bike" watts to save with hacksaw to those aerobars too!

No? Well FWIW, my estimated CdA when on that very same white P2T is 0.020-0.030 m^2 higher than aboard my old Hooker - at typical race speeds, this equates to 20-30 W.

Different helmet, no shoes covers, different wheels and tires. Position is essentially the same, the data have been corrected for differences in air density, and the tracks are comparable in terms of surface.


Correct - and they were glued on with the modern equivalent of shellac, so they should have rolled as well as any tubular.


Even on an indoor track (and/or under windless conditions outdoors), yaw angle on the track may approach 10 deg in the turns.

Data are based on multiple runs.

If necessary - however, John said that he was working on some new aero bars, so at this point who knows what will end up on the bike.

How is the riders fitness compared to the previous ride. That is a sharp looking P3T. Keau

Why would their fitness matter? Power is power, regardless of how it is generated.

Call me crazy but I'm skeptical as to how this works out.

To be honest, I'd be just as skeptical, if not for the fact that all of the data I've collected over the last couple of years suggests that such a difference should exist.

with so many variables both helping and hurting the watts required for the same speed on both runs, it just seems like a 20-30w difference just between the frames is a little outlandish. I mean, 28.67mph is fast, but still very real world for a lot of riders. Raising ftp by 20w takes time! Maybe it's better to break out the cc and get a p3! - E

Rider's weight the same? Bike weight the same?

Rider's weight is the same. The P3C is probably a little lighter than the P2T (I haven't weighed them), but the difference is really meaningless in the big scheme of things (flat track, constant speed, no significant difference in non-bike mass).

Accuracy of the powermeter?

So my question is, if she's capable of putting out 344W for repeated runs on the first bike, why didn't she ride at 344W for the runs on the P3C?

Drum roll please......

Are those Power Cranks in disguise in the second pic?

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I'm just a 10 cent rider on a $2,500.00 Bike

Actually, she didn't do repeated flying 3:54s on either bike - I just chose that time/speed/distance as a handy one for comparison.

(The raw data upon which I based the P2T power estimate can be found in Table 5 of this document: http://www.cyclingpeakssoftware.com/...rTrainingChapter.pdf)

P.S.: I suggested to this rider that perhaps they should do an all-out 3 km (from a standing start), just to see where they stood fitness-wise. They refused, and when asked why, replied "because they hurt like a mo' fo'!!!"

It's the same SRM, calibrated using the same set of weights.