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Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
where is trek ttx?
maybe their white paper was right after all
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S�rgio Marques
When it hurts is when it feels good ;-)
Sergio-Marques.com
maybe their white paper was right after all
=====================================
S�rgio Marques
When it hurts is when it feels good ;-)
Sergio-Marques.com
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
curious re: the absence of the TTX.
Any thoughts?
Jeff Shilt
__________________________
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twitter @MdotDoc
Any thoughts?
Jeff Shilt
__________________________
www.mdotdoc@blogspot.com
twitter @MdotDoc
Re: P4 Drag Numbers [Dr. J]
[ In reply to ]
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
Oh...and does anyone know if the positive yaw direction is with the wind hitting the DS or NDS?
http://bikeblather.blogspot.com/
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
....it also looks like the reported "30s over 40K vs. a P3" is slightly conservative ;-)
http://bikeblather.blogspot.com/
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
The TTX is missing and I'd be interested to see it in the mix.
Tom Demerly
The Tri Shop.com
Tom Demerly
The Tri Shop.com
Re: P4 Drag Numbers [Tom A.]
[ In reply to ]
where is the hotta, lotus and hooker :P
=====================================
S�rgio Marques
When it hurts is when it feels good ;-)
Sergio-Marques.com
=====================================
S�rgio Marques
When it hurts is when it feels good ;-)
Sergio-Marques.com
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
Interesting. Forgive my ignorance, but why do you suspect the numbers for negative and positive angles beyond 5 degrees are so asymetrical (different) for the P4 while most other frames seem fairly symmetrical? Do the negative degree numbers represent the non-drive side or drive side of the bike? Also curious why numbers don"t go up to 15 degrees on both sides.
...
Hoka One One (Hawaii)
facebook.com/hokaoneonehawaii
...
Hoka One One (Hawaii)
facebook.com/hokaoneonehawaii
Re: P4 Drag Numbers [sergio]
[ In reply to ]
Can't help you with the hotta, and Andy's posted numbers on the Hooker...but this (the top plot) shows the Lotus:
http://bikeblather.blogspot.com/
Re: P4 Drag Numbers [Tom A.]
[ In reply to ]
at 8deg yaw on the chart, what would you estimate based on the numbers above, P4 vs P3 over 40k?
Re: P4 Drag Numbers [gtingley]
[ In reply to ]
By my "eye"...average of +/- at that yaw looks to be ~45s over 40K...assuming these drag values are measured at 30mph (I REALLY wish they'd just report the values as "CdA" or "CxA" so we wouldn't have to worry about the speed, air density, etc....OK, rant off ;-)
http://bikeblather.blogspot.com/
Re: P4 Drag Numbers [gtingley]
[ In reply to ]
Eyeballing the chart and averaging the L/R figures at ~8 degrees...lets call it 100g reduction. Using AC's ROT, that's about equal to 40 seconds over 40K.
EDIT: Thanks, Tom...I guess you can beat me at a typing race, too. ;)
"100% of the people who confuse correlation and causation end up dying."
Re: P4 Drag Numbers [sergio]
[ In reply to ]
And most importantly, where is the rider? ;-)
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
I remember someone said the cheetah was a fat pig in the tunnel...any data?
Re: P4 Drag Numbers [Tom A.]
[ In reply to ]
That's pretty much hitting the "20%" mark, I'd say.
Probably would not hurt to use the structural fairing instead of the bottle.
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
Thank you very much for sharing this data with us. Now that they did most on the engineering work on another great product they hopefully still have some time left for a "the first ever" sexy Cervelo paint job ;)
�The greater danger for most of us is not that our aim is too high and we miss it, but that it is too low and we reach it.� -Michelangelo
MoodBoost Drink : Mood Support + Energy.
�The greater danger for most of us is not that our aim is too high and we miss it, but that it is too low and we reach it.� -Michelangelo
MoodBoost Drink : Mood Support + Energy.
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
Thanks for sharing. I, too, would have liked to have seen the TTX on there for comparison sake.
Also, the P2 is one hell of a value based on the below graph! It's around 1/2 the price of the P3 (frameset) and just a fraction less aero.
Also, the P2 is one hell of a value based on the below graph! It's around 1/2 the price of the P3 (frameset) and just a fraction less aero.
Re: P4 Drag Numbers [gtingley]
[ In reply to ]
Hehe...that "bottle" has me thinking of a "cozy" I could put on my Bonty Speed Bottle on the P2K...of course, it's only "purpose" there will be insulation for the bottle. You know, to keep the contents cold ;-)
http://bikeblather.blogspot.com/
Re: P4 Drag Numbers [sergio]
[ In reply to ]
I was wondering the same thing. I guess taking the biggest threat away from the P4 you can make the numbers look good.
Owner of a few Speed Concepts since 2011.
Owner of a few Speed Concepts since 2011.
Re: P4 Drag Numbers
[ In reply to ]
More than anything, I'd like to see all of the bikes pictured as tested. Does anyone know how the bikes were tested (i.e. w or w/o disc wheels, cables?, P4 tested with bottle, etc.)?
It's easy to see 50-150 gram differences in the tunnel due to stem variations, steerer lengths, etc.
And an additional repeat of one or more bikes would be great too.
Looks like the frame and fork are a huge improvement over the P3C, no doubt. I bet they gain 75-100 grams of drag just from improved tube shapes (especially the fork).
Mark
It's easy to see 50-150 gram differences in the tunnel due to stem variations, steerer lengths, etc.
And an additional repeat of one or more bikes would be great too.
Looks like the frame and fork are a huge improvement over the P3C, no doubt. I bet they gain 75-100 grams of drag just from improved tube shapes (especially the fork).
Mark
Re: P4 Drag Numbers [Andrew69]
[ In reply to ]
I want wind tunnel numbers for
TTX, Specialized Transition, Look 596 throw a Ceepo in there too
if some one dose this they will be my hero.
Kerry Sullivan
USAT,USACII, CSCS, NLP practitioner
http://www.triathlonsummit.com
TTX, Specialized Transition, Look 596 throw a Ceepo in there too
if some one dose this they will be my hero.
Kerry Sullivan
USAT,USACII, CSCS, NLP practitioner
http://www.triathlonsummit.com
Re: P4 Drag Numbers [MITaerobike]
[ In reply to ]
I agree...that would be great. What you touch on above shows just how easy it can be to "sandbag" a particular model in the testing, even if it's their own ;-) Anyone besides me think the "fixed offset" of the P2C vs. the P3C is a bit too convenient??
Then again, I guess we're lucky to see this data in the first place...
Another thing nobody has commented on is the conspicuous absence of the Transition in that chart. Mark, do you have any input on where that bike would stand in the mix?
http://bikeblather.blogspot.com/
Just guessing here...but I'd bet that the water bottle partially shields the crank when the wind is from the non-drive side.
"100% of the people who confuse correlation and causation end up dying."