Being more upright would be a benefit with a tail wind if and only if the tail wind is faster on average than your average speed. If the tail wind is slower than you, the TT bike is aerodynamically advantageous, although by less so than with no wind or a headwind.

Ah - cheers will have to google so I understand..

We can argue what people should do at what speeds all day, but the reality is what I described....most people are out of aero well before 12-13 mph.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

If you extrapolate down from tests done at 30 mph in a wind tunnel possibly, but on the road at those speeds, are you sure?

Only if you're traveling slower than the tailwind...think about it ;-)

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http://bikeblather.blogspot.com/

Really? In all situations? How much time?

Yes, I'm sure. Try analyticcycling.com if you don't believe me.

You, of all people ?! I really hope you're pulling my leg! Because if you truly don't get it, then you are leaving time on the table, and you of all people should not be leaving time on the table. If you were in my age group I'd tell you to go ahead and ride your road bike! ;^>

The answers are "Yes", "No", and "It depends". I'm only being the tiniest bit flippant.

Go to analyticcycling .com. There are several different calculators that would work - I tried http://www.analyticcycling.com/WheelsClimb_Page.html

Enter the following: Note: everything is identical except CdA ("Frontal Area" * "Coefficient Wind Drag"). You have to be a little careful with the calculator because it apparently rounds those two inputs to one significant figure. I used values of .24 (0.6*0.4) for a TT bike and .28 (0.7*0.4) for road bike. In most cases the difference in CdA between road bike and TT bike would be greater than .04, so this is a conservative estimate.

Data Parameters Parameter Standard Rider Test Rider
Frontal Area 0.6 0.7 m2
Coefficient Wind Drag 0.4 0.4 dimensionless
Air Density 1.226 1.226 kg/m3
Weight Rider 65.0 65.0 kg
Weight Bike 8.0 8.0 kg
Front Wheel
Weight 1.300 1.300 kg
Ic 0.0900 0.0900 kg m/s2
Cx0 0.0500 0.0500 Dimensionless
Radius 0.337 0.337 m
Rear Wheel
Weight 1.800 1.800 kg
Ic 0.1000 0.1000 kg m/s2
Cx0 0.0491 0.0491 Dimensionless
Radius 0.337 0.337 m
Rear Shelter 25. 25. %
Power 300. 300. w
Coefficient of Rolling 0.004 0.004 dimensionless
Grade 0.05 0.05 decimal
Initial Speed 0.0 0.0 m/s

(sorry about the format)

The results? "At the end of 8000m Standard Rider is ahead by 19.91s and 124.97 m."

Go ahead and run it yourself. That's a 5 mile, 5% grade climb. Speed ends up being a bit over 6 m/s (22 km/hr).

Any more questions?

"It depends" and "everything is identical" answers all my questions.

Ok - I did the hill this morning on my road bike, (I'm actually I'm 90KGs, plus the bike, probably 7.5KGs with water and seat pack.)


According to wko+, the gradient was 5.2% @ 4.92 miles


for 300 watts (301NP) I averaged 11.4 mph , 25:42, 117 place, (3rd on same hill with an actual powermeter is; 351 watts for 18:28, 15.8 mph)



http://www.strava.com/...50067?filter=overall


If I try TT bike I'll post result.

That's pretty similar to Bear Mtn near where I live.
Tri bike all day, every day, and twice on Sundays. There is a definite aero benefit, even at those speeds.
(like Jackmott, I don't lose any watts on my TT bike)

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float , hammer , and jog