How much BHP from a push bike.

[Thomas. PLease.]

Right, me and a friend were thinking about this the other day.

Hypothetically, how many bhp/lb ft. of torque do you think it would be possible to generate on a push bike? on a rolling road.

i think a fit person would maybe generate 1 and a bit maybe two horsepower?

what to you guys think?

 

[[TW]Fox]

You think a person has the power of two horses?

Try 0.25-0.5.

 

[MikeHunt79]

I'd guess around 1-2. I'd like to give it a go, even tho my fitness isn't what it once was...

 

[peterattheboro]

Less than 1 i'd say?

Around 0.4?


Damn Fox.

 

[PinkFloyd]

You think a person has the power of two horses?

Definitely less than 1.
Get a tandem

 

[Conscript]

If a man could generate 2hp, do you think we would have relied on them for so long?

 

[[DOD]Asprilla]

1 BHP is 0.74Kw.

If you jump on a decent execercise bike it will tell you how many Kw you are producing.

 

[MikeHunt79]

1hp = 750W.

I guess if you could somehow get your bike to drive a generator, you could see how many watts you could do.
I'm sure some sports fitness person may be able how many joules (isn't a watt 1 joule per second) you can burn, and do it all with maths, but that's not as fun as a rolling road...

I guess a real horse will do more than 1hp!

 

[Thomas. PLease.]

You think a person has the power of two horses?

Try 0.25-0.5.

yeh but who has actually measured the horses, plus given the right conditions people can go a lot faster than horses.

 

[doofer]

I just want to see a horse riding a bike! I don't care about the HP.

 

[InvaderGIR]

yeh but who has actually measured the horses, plus given the right conditions people can go a lot faster than horses.

Go to the gym, see what the bikes there say.

InvG

 

[Conscript]

yeh but who has actually measured the horses, plus given the right conditions people can go a lot faster than horses.

What conditions exactly? I want to see an average human outrun a galloping horse. Until then, your statement holds no water.

 

[Lashout_UK]

http://www.youtube.com/watch?v=-S_2VoCru8M

Nobody got 1 hp.

 

[Skiddley]

Wikipedia;

"Put into perspective, a healthy human can produce about 1.2 hp briefly (see Orders of magnitude (power)) and sustain about 0.1 hp indefinitely, and trained athletes can manage up to about 0.3 horsepower for a period of several hours."

Horsepower of a horse;

"R. D. Stevenson and R. J. Wasserzug published an article in Nature 364, 195-195 (15 July 1993) calculating the upper limit to an animal's power output. The peak power over a few seconds has been measured to be as high as 14.9 hp. However, for longer periods an average horse produces less than one horsepower."

I suspect that a bike isn't the most efficient way for a human to use energy (given physiology) and as such a humans' output on a bike would be well under 1hp. One would also have to consider transmission loss from the crank to the tyre also

 

[Dave]

yeh but who has actually measured the horses, plus given the right conditions people can go a lot faster than horses.

Horsepower isn't to do with speed, it's a unit of power. I'm not sure that many people could run quicker than a horse either!

 

[nicRob]

IIRC one of the guys at Powerstation said they'd put a pushbike on the rollers once..can't remember anything else tho

 

[Thomas. PLease.]

hm, yeh that 1.2 horse power sounds right, and a sustained 0.1 effort, which is what most people seem to be true

thanks

 

[Thomas. PLease.]

http://www.youtube.com/watch?v=3L8hO7tD_OI&feature=related

 

[Skiddley]

So more interestingly. Fred flintstone's car had a sustained output of 0.1hp. And it's made of stone....and he's a fat git. Go figure.

 

[Richdog]

yeh but who has actually measured the horses, plus given the right conditions people can go a lot faster than horses.

What, up stairs and climbing frames?