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The world's fastest human-powered vehicle tops 85 mph

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Re: The world's fastest human-powered vehicle tops 85 mph

#11

Post by yurisagalov »

irl_zebra wrote: post #4

I'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…

Todd is actually a world-class rider (based on the chart you provided, as well).

From the article before they won the Sikorsky prize:

"Reichert, a national-level speed skater, can pedal at 1.2 horsepower for a full minute"

http://m.thestar.com/#/article/news/gta/2012/08/26/humanpowe...

Re: The world's fastest human-powered vehicle tops 85 mph

#12

Post by QuotedForTruth »

irl_zebra wrote: post #7
luminiferous wrote: post #6

Earlier quoted context omitted.

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.

Actually, on a flat surface with a constant speed or acceleration, weight matters much, much less than frontal area. Weight comes into play much more when many quick accelerations or elevation gains come into play. Because frontal area doesn't increase proportionally with weight, I would argue that power output should be the primary concern and that typically increases substantially with weight. For evidence of this,…

Track sprinters are even bigger, further showing your point. Chris Hoy is 205 lbs.

Re: The world's fastest human-powered vehicle tops 85 mph

#13

Post by davidw »

irl_zebra wrote: post #7
luminiferous wrote: post #6

Earlier quoted context omitted.

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.

Actually, on a flat surface with a constant speed or acceleration, weight matters much, much less than frontal area. Weight comes into play much more when many quick accelerations or elevation gains come into play. Because frontal area doesn't increase proportionally with weight, I would argue that power output should be the primary concern and that typically increases substantially with weight. For evidence of this,…

Exactly.

https://en.wikipedia.org/wiki/Tony_Martin_(cyclist) weighs in at 75 kg - lighter than Cancellara - but not that light for a professional cyclist either.

Re: The world's fastest human-powered vehicle tops 85 mph

#14

Post by darkstar999 »

drpgq wrote: post #8

I 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.

Would the multiplied power be offset by the multiplied weight and potential loss of aerodynamics?

Re: The world's fastest human-powered vehicle tops 85 mph

#15

Post by QuotedForTruth »

drpgq wrote: post #8

I 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.

Im sure the rules state 1 human. That is an interesting thought though. A second person behind the first would add very little extra drag while doubling the power.

Re: The world's fastest human-powered vehicle tops 85 mph

#16

Post by irl_zebra »

QuotedForTruth wrote: post #9
irl_zebra wrote: post #4

I'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…

You could really probably optimize for the 200m speed zone. As long as you can get to your top speed before it, you dont need to fly through the 5 mile zone. Better to save energy for an explosive finish. Track cyclists sometimes do a "flying 200m." The record is 9.347 seconds which is 47.86 mph. Thats on a non aero bike with drop handle bars. It would be very interesting to see them in a perfectly aero recumbant bik…

Absolutely. Being trained for such short intervals, I wonder how much their power output would drop in the final 200m after that 5 mile buildup. In any case, there has to be some optimal cyclist build for this event. I suspect it's probably somewhere between a time trialist and a pure sprinter.

Re: The world's fastest human-powered vehicle tops 85 mph

#17

Post by Semiapies »

drpgq wrote: post #8

I 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?

Re: The world's fastest human-powered vehicle tops 85 mph

#18

Post by davidw »

darkstar999 wrote: post #14
drpgq wrote: post #8

I 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.

Would the multiplied power be offset by the multiplied weight and potential loss of aerodynamics?

As someone wrote above, weight doesn't matter that much, and since the most likely configuration would be one behind the other, the aerodynamics wouldn't suffer that much.

Re: The world's fastest human-powered vehicle tops 85 mph

#19

Post by irl_zebra »

yurisagalov wrote: post #11
irl_zebra wrote: post #4

I'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…

Todd is actually a world-class rider (based on the chart you provided, as well). From the article before they won the Sikorsky prize: "Reichert, a national-level speed skater, can pedal at 1.2 horsepower for a full minute" http://m.thestar.com/#/article/news/gta/2012/08/26/humanpowe...

EDIT: Made a mistake with the numbers!

This is interesting; 1.2hp is about 895 watts. Assuming he's probably 65kg (total guess from the looks of him). That means he can do about 13.7 Watts/KG for 1-minute. According to the chart I posted above, looking at 1 minute power, that puts him as a Far to Moderate level cyclist. Even giving the benefit of the doubt and assuming 55kg, making the ratio a better 16.2 Watts/KG, that just moves him up to the "Good" category.

So perhaps a lot of improvement could be had moving to a professional cyclist.

Re: The world's fastest human-powered vehicle tops 85 mph

#20

Post by sandworm101 »

Typical Canadians. Their country's flag is smaller than the GMC logo. I hope someone from UofT alumni relations gives them a call.

If you are going for a speed record, you need something more like this: http://cdn.rsvlts.com/wp-content/uploads/2014/02/olympics-sk...

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