How much power does a bike have?

[beyond rational]

Ok brain trust....

Here is a question that has been on my mind, I realise it has a few variables such as crank length, riding posistion etc. but what is the torque of an "average" rider and say, a professional?

Edited by beyond rational on Tuesday 27th March 13:29

[mat205125]

Crank length, gear, etc etc etc has nothing to do with how much power and torque the "engine" of the bike can produce.

Not sure how accurate the exercise bikes are in the gym, but they typically show that I cycle at about 200W (right units?) on a long session. I'd never try and make out I was anything but a weekend fun biker BTW - climbs are just a chore to enjoy the flat and downhill.

Peak "power" and "torque" would come from a body shape more like a power lifter or strong man than a cyclist for a brief spurt.

I'm just rambling now, and not helping answering your question

[beyond rational]

Ok,more specfic, if you put a dynamometer on the end of the bottom bracket (in this instance crank length does matter) what would be the results??

[Neil_Bolton]

beyond rational said:

Ok,more specfic, if you put a dynamometer on the end of the bottom bracket (in this instance crank length does matter) what would be the results??

Isnt there some fancy chainset that someone makes that does this? Hope or Middleburn or the likes.

I know that you can buy the stupidly expensive £6.5k SRM Cannondale that has a chainset that measures power output... http://gb.cannondale.com/bikes/07/ce/

Edited by Neil_Bolton on Tuesday 27th March 16:29

[mat205125]

Surely to measure power, you must take a sample of the power like a rolling road.

[beyond rational]

No need for a rolling road though, the whole point of them is usually working out crank HP anyway so may as well go as near to the source as possible and avoid all of those frictional losses.

That chainset sounds interesting Neil, I'll look into it, I don't want one, but I wonder if someone with one has been sad enough to post results

[rico]

Further on what Neil said... http://en.wikipedia.org/wiki/Cycling_

[Neil_Bolton]

rico said:

Further on what Neil said... http://en.wikipedia.org/wiki/Cycling_

Holy Shit!

I've just shat me pants at the prices of those chainsets!!!

www.srm.de/store/index.php?cat=c10_Road.html

[Nick_F]

You can put power measurement on a road bike for less than a grand.

www.planet-x-bikes.com/triathlon/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=285

I think the rule of thumb is that you need to be able to produce about 7w per kg of body mass to be a contender in the TdeF - measured over a kilometre or so in a 'Functional Threshold Power' test.

[GreenV8S]

I seem to remember that a fit human can put out of the order of 1 bhp very briefly, and sustain something like a tenth of that.