While watching this, a thought occurred in my head: for these types of challenges, are the participants tested for PEDs and such?
The world's fastest human-powered vehicle tops 85 mph
41–50 of 112 posts
Re: The world's fastest human-powered vehicle tops 85 mph
#42I'm guessing something can't get much more aerodynamically shaped? I wonder if they used a power meter to measure the driver/rider's power output and whether the driver was an accomplished cyclist. It seems that at this point, it would simply be a matter of getting a stronger cyclist, say someone like Brad Wiggins who can push 430 watts for an hour over an amateur, but still respectable rider, who puts out something…
I would imagine that power to weight ratio is more important than just the power. Also the smaller the cyclist, the smaller they can build the aerodynamic shell, thus reducing drag.
Air drag is proportional to the front facing area of the vehicle, that is 2nd power of cyclists dimension (for example, height, we are assuming that humans have approximately similar shape, regardless of size). Max power grows to 3rd power of cyclists dimension, because it's dependent on the cyclists muscle mass. Maximum aerobic power grows somewhere between 2nd and 3rd power, because of the fractal shape of lungs and veins (for example, think about lung surface area, the smallest folds in lung have same dimension in bigger and smaller guys, so the area grows faster than 2nd power of cyclist's dimension).
It then follows that bigger guys do well pushing against air (since frontal area grows slower than maximum aerodynamic capability), and smaller guys do better dragging themselves uphill (since mass grows faster aerodynamic capability). You can easily find practical examples of this: say Fabian Cancellara, who has won time trial world championships 3 times + almost anything else riding in fairly flat ground, including several tour prologues and stages before getting into mountains... but when you get to the mountains, it's the featherweights that rule, so likes of Cancellara can't ever win the tour.
So... to propel something as fast as possible against air, you need big and strong cyclist (with huge lungs to match), just like the guy in the video looks like. Power/weight has little to do with it, since air drag is most of the resistance, and they can accelerate for 5 miles before measuring speed (you would need power/weight if you needed to accelerate fast, which is not the case).
Re: The world's fastest human-powered vehicle tops 85 mph
#43Picture on top has new Google logo on it, video at 3:49 shows old Google logo on the vehicle.
Re: The world's fastest human-powered vehicle tops 85 mph
#44Picture on top has new Google logo on it, video at 3:49 shows old Google logo on the vehicle.
That video is from last year's attempt.
Re: The world's fastest human-powered vehicle tops 85 mph
#45Earlier quoted context omitted.
Max speed has very little to do with weight as long as you have sufficient room to accelerate. Additional drag would be small if you put one rider in front of the other and both inside of a fairing. The frontal area and shape could stay the same. This is the major source of drag. There would be small amounts of additional drag from the air running along a longer fairing, but doubling the power would more than make up…
Drag is approximately proportional to the square of the velocity, not cube.
Drag force is proportional to 2nd power of velocity, power lost to drag is force*speed, which is 3rd power of velocity.
Re: The world's fastest human-powered vehicle tops 85 mph
#46I wonder why for fastest human-powered they don't use more than one cyclist. I assume with eight humans like in rowing you could get up to a ridiculous speed. Might be a little dangerous though.
This isn't horribly safe, either. Wiping out at 85 MPH would suck . I'm curious what multi-cyclist vehicles could do, now that you suggest it. With the lightness of these vehicles, at what point would you have to add spoilers?
The video shows one crash last year. It didn't actually appear to be that bad. The shell would presumably spare you some nasty road rash at least.
Re: The world's fastest human-powered vehicle tops 85 mph
#47I'm guessing something can't get much more aerodynamically shaped? I wonder if they used a power meter to measure the driver/rider's power output and whether the driver was an accomplished cyclist. It seems that at this point, it would simply be a matter of getting a stronger cyclist, say someone like Brad Wiggins who can push 430 watts for an hour over an amateur, but still respectable rider, who puts out something…
"I'm guessing something can't get much more aerodynamically shaped?"
The previous record holders claim otherwise. On May first, they wrote (http://www.hptdelft.nl/en/blog.php):
"Actiflow has assisted us in computational fluid dynamics software in order to further optimize the promising shape of the VeloX IV. The result: a mature aerodynamic design with 10% less drag!"
They also write that this design is optimized for the 200m sprint. Their previous designs also were made for a one hour time trial, but this design doesn't take in enough air for the rider that long.
Re: The world's fastest human-powered vehicle tops 85 mph
#48I'm guessing that the rules prohibit using some of the pedal power to charge a battery during the initial part of the run, and then using that stored energy to provide an additional speed boost :D
Re: The world's fastest human-powered vehicle tops 85 mph
#49I'm guessing that the rules prohibit using some of the pedal power to charge a battery during the initial part of the run, and then using that stored energy to provide an additional speed boost :D
I don't see why not. The initial run is essentially the storing up of momentum. From that, running up a flywheel inside the bike is just storing the same energy in a different place.
Re: The world's fastest human-powered vehicle tops 85 mph
#50I'm guessing that the rules prohibit using some of the pedal power to charge a battery during the initial part of the run, and then using that stored energy to provide an additional speed boost :D
I don't see why not. The initial run is essentially the storing up of momentum. From that, running up a flywheel inside the bike is just storing the same energy in a different place.
It stretches the concept of "human powered". Why not just pedal while stationary to charge a battery (take as long as you like), and then ride the course with no additional expenditure of effort.