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Mess with your minds: A wind powered craft going faster than a tail wind speed.
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thm_w:

--- Quote from: BrianHG on December 15, 2021, 11:43:50 pm ---Most of that excess power difference is due to rubber tires on asphalt which is really affected by tire pressure.
I know that over-inflated 125psi high pressure narrow racing tires take half the effort compared having the same tires inflated to 80psi.  Even worse compared to fat underinflated mountain-bike tires.

Like a train, if your bike had metal wheels driving on a flat steel beam, then wind preasure would be more dominating.

--- End quote ---

Definitely not half the effort for slightly higher inflated tires.
The difference in rolling resistance for 100 vs 120psi on GP5000 tires at 29km/h is ~0.7W: https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-5000-2018
So 80 vs 125psi would be ~3W at most (10-13W total).

Sure fat mountainbike tires will be worse, but, calculator is not using them.



--- Quote ---Also, the wattage in that calculator, it that the human muscle exertion's calorie burn, or torque at the pedals?
--- End quote ---

When we talk about wattage on a bike, its power going into the pedals, not humans actual watt output, which would be much higher and vary depending on the individual.


--- Quote ---Yes, the wind is still a major factor as it also pushes on every moving surface.
--- End quote ---

Yes, if you can find another way to calculate that power, can post it.
If we use a wind turbine calculator its about 20W, but, no idea if that is relevant here.



--- Quote from: electrodacus on December 15, 2021, 11:51:20 pm ---OK :) I needed to have fun so apparently a human has no problem pedaling upwind at 1km/h with headwind of 230km/h
(Attachment Link)

--- End quote ---

Keep in mind 300W is not "no problem" for most people, its a lot of effort.
electrodacus:

--- Quote from: thm_w on December 16, 2021, 12:48:28 am ---

--- Quote from: electrodacus on December 15, 2021, 11:51:20 pm ---OK :) I needed to have fun so apparently a human has no problem pedaling upwind at 1km/h with headwind of 230km/h
(Attachment Link)

--- End quote ---

Keep in mind 300W is not "no problem" for most people, its a lot of effort.

--- End quote ---

300W is within most humans capabilities now some in better shape can sustain that for much longer than others.
Now just consider that is a fit person and can sustain those 300W. Do you know what 230km/h sustain speed means ?
That person even if tied to the ground will have the meat removed from the bones.


230km/h is about 143mph not gust sustained.
Anyone that builds such an online calculator should test the extremes to see if it makes sense and if not he will be able to realize something is wrong.
Just notice you are Canadian so you know what km/h are.
electrodacus:
Let me improve the explanation (maybe I make it worse but I want to try).

You have one of those 40% propeller based wind turbines and you put one of those on a vehicle and say swept area is 1m^2 just for simplicity.

In 10m/s wind while the turbine is stationary it will produce  0.5 * 1.2 * 1 * 10^3 * 0.4 = 240W
Now say there is no wind but you drive with the turbine on top of your vehicle at 10m/s (vehicle speed no wind speed).
Will the turbine not produce the same 240W ?
If not why not ? 
bdunham7:

--- Quote from: electrodacus on December 16, 2021, 01:14:52 am ---Do you know what 230km/h sustain speed means ?
That person even if tied to the ground will have the meat removed from the bones.

--- End quote ---

So how do people go that fast on motorcycles without being defleshed?  It's a lot of wind and the turbulence might be tough on a bicycle, but if you were on a heavy, stable pedal-driven machine with approximately the frontal area of an upright rider you could indeed pedal into a 230km/h wind.
electrodacus:

--- Quote from: bdunham7 on December 16, 2021, 01:21:33 am ---
--- Quote from: electrodacus on December 16, 2021, 01:14:52 am ---Do you know what 230km/h sustain speed means ?
That person even if tied to the ground will have the meat removed from the bones.

--- End quote ---

So how do people go that fast on motorcycles without being defleshed?  It's a lot of wind and the turbulence might be tough on a bicycle, but if you were on a heavy, stable pedal-driven machine with approximately the frontal area of an upright rider you could indeed pedal into a 230km/h wind.

--- End quote ---

People on a motorcycle are shielded by the motorcycle body there is no 0.5m^2 of human exposed to those speeds.
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