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If its a sprint, then it's really difficult to estimate due to too many variables. If its a seated position you can use http://analyticcycling.com/ForcesPower_Page.html and get an approximation (wind and road conditions play a big role). If you want a better power estimate, time how long it takes to climb a steep (6%+) hill and use the analyticcycling website to calculate power.
 

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How much do you weigh? What is your cda? Are you drafting? Gradient of the road; wind speed?

34mph / 55km/hr is probably a stand up sprint. If it's solo, on flat ground, with no wind, at ~67kg, you're probably putting out about 800-900w. Give or take 200 watts...

Like function said, too much variability. Why not borrow someone's power meter?
 

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wag

iliveonnitro said:
How much do you weigh? What is your cda? Are you drafting? Gradient of the road; wind speed?

34mph / 55km/hr is probably a stand up sprint. If it's solo, on flat ground, with no wind, at ~67kg, you're probably putting out about 800-900w. Give or take 200 watts...

Like function said, too much variability. Why not borrow someone's power meter?
Agree. 900 watts should get a fairly aero person up to around 35-36 mph in a sprint. Much of that goes in to accelleration, though.

Hour record is around 34 mph? I heard about 400-450 watts average for the hour.

Every mph at those speeds takes A LOT more power.
 

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Discussion Starter · #5 ·
Fixed said:
Agree. 900 watts should get a fairly aero person up to around 35-36 mph in a sprint. Much of that goes in to accelleration, though.

Hour record is around 34 mph? I heard about 400-450 watts average for the hour.

Every mph at those speeds takes A LOT more power.
Wow I have generate such power....I never thought about it...
Anyway I want to create a power meter of myself in my trainer using generator...
anyone has a link about it ?
 

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On flat ground body weight won't matter, the question was maintaining the speed, not getting up to it. The power generated is independent of gearing. Given constant natural surrounding (gradient, wind, road conditions) power is a function of speed (including its changes) alone.

-ilan
 

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Discussion Starter · #7 ·
ilan said:
On flat ground body weight won't matter, the question was maintaining the speed, not getting up to it. The power generated is independent of gearing. Given constant natural surrounding (gradient, wind, road conditions) power is a function of speed (including its changes) alone.

-ilan
Where can I find this function in the net ?
Thanks ..
 

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maintain 34 mph?

ilan said:
On flat ground body weight won't matter, the question was maintaining the speed, not getting up to it. The power generated is independent of gearing. Given constant natural surrounding (gradient, wind, road conditions) power is a function of speed (including its changes) alone.

-ilan
I would bet that no one who has ever even visited this forum can maintain 34 mph, solo on flat ground. That is really, really, really, really, really, really, really hard. That would be hard for a Lance Armstrong.
 

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ilan said:
On flat ground body weight won't matter, the question was maintaining the speed, not getting up to it. The power generated is independent of gearing. Given constant natural surrounding (gradient, wind, road conditions) power is a function of speed (including its changes) alone.

-ilan
Wrong. Although mass is less of a concern than CdA, it is still a variable in the calculation and cannot be ignored.

And how do you know the question was about maintaining speed?
 

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Fixed said:
I would bet that no one who has ever even visited this forum can maintain 34 mph, solo on flat ground. That is really, really, really, really, really, really, really hard. That would be hard for a Lance Armstrong.

I'm sure some of the better TT guys can do it. Its all about the aerodynamics at that speed.
 

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Amsmoore said:
I'm sure some of the better TT guys can do it. Its all about the aerodynamics at that speed.
Perhaps Boardman at his peak on a wooden velodrome in the now illegal super aerodynamic Superman position, but that's about it.

For a road TT, even a slick rider (CdA ~ 0.22 m^2) would require in the order of 6.6W/kg watts to hold that sort of speed on a flat road.

That sort of power is in the realm of the exceptionally talented rider who also dopes.
 

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Alex_Simmons/RST said:
Perhaps Boardman at his peak on a wooden velodrome in the now illegal super aerodynamic Superman position, but that's about it.

For a road TT, even a slick rider (CdA ~ 0.22 m^2) would require in the order of 6.6W/kg watts to hold that sort of speed on a flat road.

That sort of power is in the realm of the exceptionally talented rider who also dopes.
I bet a lot of guys can maintain that speed. Not for long though. 55kph is a 13.1 second 200m ITT, I think many Cat 3 riders and almost all Cat 2's can do that.

-ilan
 

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Discussion Starter · #16 ·
bianchi77 said:
Thanks a lot for the formula, I understand that too...:)
Sometimes, when I'm climbing in 10% to 15% gradient, how much power do I need for 12 km/h ? How can I maintain / train my breath ?
I lose my breath if it's long long long climb ...

Anyone has same experience with me...how to overcome that ?
 

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instead of posting endless questions about your power input (this and other threads) why not buy yourself a power meter. That plus cyclingpeaks WKO software equals an excellent way to train. Otherwise, knowing your power output as per these questions is nothing more than some trivia. The purpose of power is to have an objective metric for training/racing and to use the training metrics that can be derived from it, such as training stress score and the performance mangagement tools of WKO.
 

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ilan said:
I bet a lot of guys can maintain that speed. Not for long though. 55kph is a 13.1 second 200m ITT, I think many Cat 3 riders and almost all Cat 2's can do that.

-ilan
But that's not maintaining the speed. That's a sprint. Cippollini might put out 2,000 watts for 200m, however you still wouldn't say he was maintaining 42 mph speed.

Fact is, for any ride of some length, say 45 minutes even, 34 mph is outside the realm of possibility for virtually every person on Earth (for flat, no wind ride).

The hour record on a Merckx era bike isn't even close to that. The fastest times in TdF history are barely that, and in all occasions there was a tailwind and maybe even slight loss in elevation over the course (Zabriskie, LeMond, Armstrong).
 
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