Maximum Human Torque
07-08-13, 03:51 AM
#51
Newbie
Join Date: Jul 2013
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Because it takes POWER to go fast, and power is force multiplied by speed, or in this case pedal torque multiplied by rotational rate (cadence). If your torque is indeed higher throughout (which I doubt), his cadence at the lower torque level he is at, is sufficiently greater than your speed.
Let's say a sprint finish for Robbie McEwen requires him to put out 500 W. His gear is 53/11 and he's riding on 20 mm tyres. Let's also assume that the sprint is at 60 km/h. 60 km/h is 16.7 m/s, and the circumference of a wheel is 2.074 m. That means ~8 wheel revolutions per second, and the 4.82 pedal-to-wheel ratio gives us a cadence of ~100, or 1.7 revs/sec. Dividing power by "second-cadence" gives torque, and 500 W / 1.7 r/s = 294 Nm. That's his average torque. Peak torque per half pedal cycle will be higher. How much higher is hard to say.
This was just an example. His actual speed and power during a sprint may well be higher. But you still calculate it the same way.
Let's say a sprint finish for Robbie McEwen requires him to put out 500 W. His gear is 53/11 and he's riding on 20 mm tyres. Let's also assume that the sprint is at 60 km/h. 60 km/h is 16.7 m/s, and the circumference of a wheel is 2.074 m. That means ~8 wheel revolutions per second, and the 4.82 pedal-to-wheel ratio gives us a cadence of ~100, or 1.7 revs/sec. Dividing power by "second-cadence" gives torque, and 500 W / 1.7 r/s = 294 Nm. That's his average torque. Peak torque per half pedal cycle will be higher. How much higher is hard to say.
This was just an example. His actual speed and power during a sprint may well be higher. But you still calculate it the same way.
07-08-13, 04:00 AM
#52
Newbie
Join Date: Jul 2013
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
This is an interesting thread. Some posters touched on what I question. On a DF if a rider is standing and his or her full weight is on one pedal, some of the numbers quoted seem low. Now if a 200 pound rider is pushing down his weight, plus the force added by pulling up on the handle bars for maybe 90 degrees the torque would seem to me would be around 250 foot pounds. That would be repeated with the other leg, for a total of 180 degrees. Then divide that by 2, because of a full 360 degree circle. Then drop that by the gearing of say 42 by 15 and you would get the torque actually applied to the ground. So to me you would have 125 times .3 would equal 37.5 foot pound of torque. Those are approx numbers for a 200 pound person and would be reduced by less weight and less pulling up on the handle bars. That would seem to me to be the max, but again that would be reduced by mechanical efficiencies. It also occurs that that would be the torque on the cassette. It would again have to be reduced by the relationship of the sprocket to the wheel depending on the size. I believe that is why my Tailwind bent would take off like a scalded rabbit with its 20 inch rear wheel. Comments?
07-08-13, 06:43 AM
#53
Banned.
Join Date: May 2013
Location: Plano, TX
Posts: 1,034
Bikes: 1982 Fuji Supreme, Specialized 2012 Roubaix Compact. 1981? Raleigh Reliant mixte, Velo Orange Campeur (in progress)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Hmm, I really need to study this subject some more. Can anyone recommend a decent tutorial site on torque forces, power, etc.?
The interesting question is: Cog and sprocket design? I thought that these components are rated for torque, not power. I wonder what the maximum torque rating is for various bicycle sprocket sizes?
The interesting question is: Cog and sprocket design? I thought that these components are rated for torque, not power. I wonder what the maximum torque rating is for various bicycle sprocket sizes?
07-08-13, 07:34 AM
#54
Banned
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 9,924
Bikes: RANS Stratus TerraTrike Tour II
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 3352 Post(s)
Liked 1,056 Times
in
635 Posts
Power or horsepower that everyone talks about is basically torque over a period of time. Torque is the thing that actually moves bikes, cars etc. Thats why trucks are tuned for max torque rather than max horsepower.
07-08-13, 09:12 AM
#55
Banned
I'm thinking Match sprint Track racers like Scottish multi world championship,
Olympic Multi Gold Medalist Chris Hoy, [Recently retired],
were, able to put out more torque on the cranks than the road guys
doing 100 miles in a road stage before the field sprint for the finish line.
Olympic Multi Gold Medalist Chris Hoy, [Recently retired],
were, able to put out more torque on the cranks than the road guys
doing 100 miles in a road stage before the field sprint for the finish line.
07-26-13, 06:22 PM
#56
Senior Member
Trucks are tuned for max torque at low RPMs because that means fewer engine cycles for a given amount of power, which means better fuel economy and longer service life. Race cars have high horsepower and high RPMs because fuel economy and engine longevity are not a priority, but maximum power to weight ratio is. A large truck engine producing 800ft-lbs of torque at 2,000rpm is effectively producing the same motivational power as a small sports car engine making 200ft-lbs of torque at 8,000rpm. The gearing is all that's different.
07-26-13, 07:19 PM
#57
Banned
Oodles of torque at the rear wheel, if the gear ratio is low enough..
like a wrench with a really long cheater pipe stuck on the end.
like a wrench with a really long cheater pipe stuck on the end.
07-26-13, 08:16 PM
#58
don't try this at home.
Join Date: Jan 2006
Location: N. KY
Posts: 5,933
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 972 Post(s)
Liked 509 Times
in
349 Posts
You can't compare pedaling a bicycle to doing 400 lb leg presses, since you're not pushing against a padded steel frame. The only reaction force that allows you to push against the cranks is the force produced by your arms pulling against the handlebars plus your body weight. Most do not have the upper body strength to pull up with that much force.
10-27-15, 06:30 AM
#59
Junior Member
Join Date: Oct 2015
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Yes yes this thread is like a century old, but I have recently become obsessed with Torque during cycling.
Does anyone know if they can make their Garmin or any head unit display Torque (Nm) recorded by their power meter? I have managed to display it but only in the calibration screen, not during rides.
I can see my Torque numbers post-ride.
Does anyone know what sort of torque measuring limits are set on power meters (for example 250Nm). As I have see many are limited to 2000w and have a rpm range of 30-200, so surely there should also be a Torque limit?
Does anyone know if they can make their Garmin or any head unit display Torque (Nm) recorded by their power meter? I have managed to display it but only in the calibration screen, not during rides.
I can see my Torque numbers post-ride.
Does anyone know what sort of torque measuring limits are set on power meters (for example 250Nm). As I have see many are limited to 2000w and have a rpm range of 30-200, so surely there should also be a Torque limit?
10-27-15, 01:16 PM
#60
Senior Member
Join Date: Aug 2009
Location: Zinj
Posts: 1,826
Bikes: '93 911 Turbo 3.6
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 109 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Muscle works like a spring. It pushes pedal down and pushes body up. Have you heard about Newton laws? If force is greater than the body weight you are just bouncing up. Yes, you can compensate for that with your arm holding handlebars tight, but not by much.
As for the Robbie, he is faster *average* moment is greater then yours, not maximum.
As for the Robbie, he is faster *average* moment is greater then yours, not maximum.
For your comment about Newton, presumably you are referring to his 3rd law, in which case, if the sum of the forces applied is greater than weight, the pedal then pushes the rider in the opposite direction in which the rider pushes the pedals in such a manner that the rider rises if the transfer of that energy is not inelastic.
Last edited by jfowler85; 10-27-15 at 01:34 PM.
10-28-15, 07:16 AM
#61
Banned
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 9,924
Bikes: RANS Stratus TerraTrike Tour II
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 3352 Post(s)
Liked 1,056 Times
in
635 Posts
Looking at it very simply, a 175 pound rider using a 175 mm crank arm could push down at about 60% of his weight in foot pounds. That figures out to approx 100 foot pounds. That would occur when the pedal is at 90 degrees. You have to understand that if pedaling torque is plotted it would be in a saw tooth. So you have to state if you are taking maximum torque or ave torque.
10-28-15, 05:32 PM
#63
Super Moderator
Join Date: Jul 2004
Location: Ffld Cnty Connecticut
Posts: 21,843
Bikes: Old Steelies I made, Old Cannondales
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1173 Post(s)
Liked 927 Times
in
612 Posts
Don't forget about the other leg pulling up.
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.
FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
06-16-17, 12:39 AM
#65
Newbie
Join Date: Jun 2017
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I am student working on a pedel assist bicycle project. You have mentioned that average torque a human can aply ia approx. 50 NM. Can u please share some written or published document where it is mentioned. I want to know the minimum force a human can apply so that motor will assist the remaining.
Thanks.
06-16-17, 04:27 AM
#66
Ride On!
Join Date: Apr 2016
Posts: 971
Bikes: Allez DSW SL Sprint | Fuji Cross
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 227 Post(s)
Likes: 0
Liked 3 Times
in
3 Posts
Don't forget how often the different 'engines' rotate here either. We're talking a human-powered, 100 RPM machine vs a 2000, 3000, 4000, (+++) RPM engine on the bike right?
So if I put out 500 lb-ft per spin and spin 100 times a minute (probably actually high for a heavy push), but a motorcycle engine puts out 200 lb-ft per spin but spins 8,000 times per minute, I have a feeling the motorcycle wins the race.
So if I put out 500 lb-ft per spin and spin 100 times a minute (probably actually high for a heavy push), but a motorcycle engine puts out 200 lb-ft per spin but spins 8,000 times per minute, I have a feeling the motorcycle wins the race.
06-16-17, 05:48 AM
#67
Senior Member
Join Date: Jul 2014
Location: Toronto, CANADA
Posts: 6,201
Bikes: ...a few.
Mentioned: 47 Post(s)
Tagged: 0 Thread(s)
Quoted: 2010 Post(s)
Liked 408 Times
in
234 Posts
Must be a good zombie thread...eleven years old, resurrected three or four times.
...motorcycle is 500+ pounds, human is 165, but motorcycle would still win.
...motorcycle is 500+ pounds, human is 165, but motorcycle would still win.
06-16-17, 11:30 AM
#68
rebmeM roineS
Join Date: Jan 2006
Location: Metro Indy, IN
Posts: 16,216
Bikes: Bacchetta Giro A20, RANS V-Rex, RANS Screamer
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 653 Post(s)
Liked 347 Times
in
226 Posts
Is Peter Tork of the Monkees involved in this somehow?
__________________
Bacchetta Giro A20, RANS V-Rex, RANS Screamer
Bacchetta Giro A20, RANS V-Rex, RANS Screamer
06-17-17, 05:46 AM
#70
Banned
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 9,924
Bikes: RANS Stratus TerraTrike Tour II
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 3352 Post(s)
Liked 1,056 Times
in
635 Posts
My two cents here. Yes not only does the cyclist on a DF bike push down on the crank with his weight, but if standing he has extra push by pulling up on the handle bars. If he does not pull up, he can only push down by the amount of his weight.
Then there are the bent riders like myself. Depending on the design of of a bent or trike, the bent rider can use their leg strength to create torque plus being able to wedge himself between the pedal and the back of the seat.
Then there are the bent riders like myself. Depending on the design of of a bent or trike, the bent rider can use their leg strength to create torque plus being able to wedge himself between the pedal and the back of the seat.
06-17-17, 10:44 AM
#71
Dirty Heathen
Join Date: Oct 2015
Location: MC-778, 6250 fsw
Posts: 2,182
Bikes: 1997 Cannondale, 1976 Bridgestone, 1998 SoftRide, 1989 Klein, 1989 Black Lightning #0033
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 889 Post(s)
Liked 906 Times
in
534 Posts
Add in clipless pedals, and get out of the saddle, and the physics get way more interesting.
Take a look at the upper body mechanics going on in the Chris Hoy video in post #58. Wow.
I'd love to put a strain gage on the stem of that rig. Heck, he's not even in the saddle untill the end of the back straight.
06-17-17, 02:16 PM
#72
Full Member
Join Date: Dec 2011
Location: SE Michigan
Posts: 464
Bikes: Serotta CRL, Litespeed Blue Ridge, Bacchetta Ti Aero, Cannondale delta V, 67 Schwinn Sting Ray stick shift.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Likes: 0
Liked 7 Times
in
6 Posts
Maximum human torque? Ask Archimedes.
09-19-17, 05:13 PM
#73
Senior Member
No body mentioned that a sprinting cyclist (especially track sprinters) is pushing down on one pedal while pulling up on the opposite pedal; plus the sprinter is also pulling up on his bars.
09-19-17, 06:12 PM
#74
Banned.
Torque
When I am standing and cranking up a steep rise my weight is not constant. Try bouncing up and pushing down on a foot scale. I am pushing down on the pedal with the momentum of my falling 225 pounds plus all the push I can muster. This must be a whopping amount because it becomes very difficult very quickly. I then morph into an air machine to try not to die before reaching the top. Now I’m on a single speed so my cadence can’t drop below a certain level or my pedals will break. Or crank. Or chain. Or B.B. done it all...a high cadence seems to get those pedals over the arc.
