Maximum Human Torque

OK, it would seem that torque is force times radius, not the way I calculated it!

I still welcome any comments though; it is rather surpring that a rider can produce several times the torque of my old motorcycle!

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topcat said:

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Hey man, thank's for your input.

Ideologue said:

I read that the maximum amount of torque momentarily produced by a professional (racing) cyclist is in the region of 1,000 Inch Pounds. That is 83.3r Foot Pounds, or 112.984 829 333 Newton Meters.

A 250cc motorcycle I used to ride only produced around 20 Newton Meters, so is the 112+Nm figure really an accurate one for the maximum torque a human can produce on a bicycle? It seems rather high to me. But then considering a rider with a mass of around 100kg standing up on the pedals and allowing his entire weight to push down on 175mm cranks (with a turning circle of 1099.6mm). This rider without even trying, and merely allowing gravity to pull his mass down and turning the cranks in the process, will exert approximately 539.35Nm of force through the bottom bracket spindle.

Rider’s weight: 981 Newtons
Distance cranks turned (at pedal): 0.54978 Meters

Riders weight divided by distance crank turned?

Now 500Nm of force sounds like a huge amount to me for a rider to exert, even for just a few seconds. That is a similar amount an average juggernaut produces. I think I have my sums wrong.

What do you make of this?

Yes, but all this will translate to considerably less torque at the rear wheel. Don't forget that even the worlds weediest motor can produce enormous amounts of torque through a lvery ow set of gears (albeit at a very low speed) and conversely, a hugely poweful motor will produce very little torque if placed through massive upgearing.

ScottishDan said:

Yes, but all this will translate to considerably less torque at the rear wheel. Don't forget that even the worlds weediest motor can produce enormous amounts of torque through a lvery ow set of gears (albeit at a very low speed) and conversely, a hugely poweful motor will produce very little torque if placed through massive upgearing.

Thanks for your reply. I am a little paradoxical in that I understand, and already realised, what you wrote yet I still get a little confused at times concerning this subject! I have some good links that I need to spend time reading that should clear it for me, although I would still be pleased to hear from anyone with anything else to offer on the topic.

I actually just posted on a bike I am designing, and how I allow for high torque, such as very low gears for towing a very heavy trailer up hill:

http://www.cyclingforums.com/showthread.php?p=2896356#post2896356

Interesting theory. I hadn't thought about it like this. It is always interesting to me how speed can vary from person to person. The torque makes a difference.
It is much more powerful to stand up and pedal. I am sure it hits more body parts too.