Ok, can anyone explain "torques"??!!
Discussion
Torque is a measure of twisting force. Think of a spanner turning a nut. The nut is the point of rotation; the axis. You apply a linear force to the spanner with your hand (and for the sake of argument, let's say your hand is right at the end of the spanner's handle.) The torque is the force applied perpendicular to the spanner, multiplied by the radial distance from the axis to the pouint at which the force is being applied to the spanner, which in our cqase is the length of the spanner ... so if you were pushing against the spanner with a force of 10 Newtons (10N is the same as the weight of 1 litre of water), and the spanner was 50cm long (which is 1/2 a metre) then you'd be applying a Torque of 10N * 1/2m = 5Nm to the nut. If you made the spanner twice as long, you'd be able to apply twice the Torque to the nut with the same amount of force applied by your hand to the spanner ... hence why it is easier to loosen a stuck bolt with a long handled spanner. It's exactly the same principle as explains a see-saw with a fat kid and a thin kid. The thin kid needs to be further away from the pivot in order to increase the torque he's applying to the see-saw so that it balance's the fat kid's torque. Similarly, th fta kid can move closer to the pivot to reduce the torque he's applying.
ATG is totally correct but I expect you want to know how this applies to you bike and the road.
Torque is the amount of ‘thrust’ an engine can generate in 1 revolution of the crank but it’s probably easiest to think of it in push bike terms with someone using the pedals. Imagine hitching a heavy trailer to be back of your push bike then trying to get the pedals to do one full turn. The effort required to get the pedals through one revolution is the torque and is measured as ATG describes. If you loaded up the trailer to the point where you could only just move it then you would be at your max torque.
Now imagine the bike being ridden by Lance Armstrong. You could easily load the trailer up more and still get the bike to move as Lance will produce more torque.
Now imagine the bike being ridden by ‘Billy the Whiz’ of Beano or Dandy fame. Billy would not be able to move the bike with the load on that either you or Lance had as he is so much smaller and lighter but – if we gear the bike down significantly and let Billy pedal many revolutions with his super fast legs in the same amount of time that it took you or Lance to do one revolution then the load will move. This is where power differs from torque.
By using gears we can make it easier for every one to move the load but you will need to pedal more revolutions to move it the same distance. As we lower the gearing and the load becomes easier to move you will need to pedal more and more to get the same total amount of movement and, very importantly, you will need to pedal faster and faster if you want to move the load the same total distance in the same time as before. Billy will manage this because of his super fast legs but you will struggle as you loegs simply wont go fast enough. This is because Billy produces more power than you.
How does that apply to your bike and the road? Well, if you look at your R6 and my VTR1000 you’ll get a good idea. Your R6 has low torque (compared to the VTR) but more power. If we both sat side by side at the same speed (say 40mph) in a gear that meant both bikes were doing 4000rpm and whacked the throttle open the VTR would disappear into the distance while the R6 was still coughing and spluttering. Now, if we both sat side by side 40mph in what we considered the best gear to accelerate forward, the R6 would be revving much much higher and would be using much lower gearing than the VTR. As we whacked open the throttle the VTR would get an initial advantage due to the torque (Lance Armstrong just stood on the pedals) but very quickly the R6 would build up more and more engine revs (Billy pedalling like mad). The VTR would soon need to go for a higher gear as it would run out of revs at about 9000rpm. As soon as the higher gear is engaged the “load” is greater thus the rate of acceleration slows. The R6 on the other hand would rev on to 14000 before needing to change gear and increase the “load” so the VTR’s initial advantage would soon be lost. After a short while the R6 would simply reel in the VTR and go past it.
Does that help?
Torque is the amount of ‘thrust’ an engine can generate in 1 revolution of the crank but it’s probably easiest to think of it in push bike terms with someone using the pedals. Imagine hitching a heavy trailer to be back of your push bike then trying to get the pedals to do one full turn. The effort required to get the pedals through one revolution is the torque and is measured as ATG describes. If you loaded up the trailer to the point where you could only just move it then you would be at your max torque.
Now imagine the bike being ridden by Lance Armstrong. You could easily load the trailer up more and still get the bike to move as Lance will produce more torque.
Now imagine the bike being ridden by ‘Billy the Whiz’ of Beano or Dandy fame. Billy would not be able to move the bike with the load on that either you or Lance had as he is so much smaller and lighter but – if we gear the bike down significantly and let Billy pedal many revolutions with his super fast legs in the same amount of time that it took you or Lance to do one revolution then the load will move. This is where power differs from torque.
By using gears we can make it easier for every one to move the load but you will need to pedal more revolutions to move it the same distance. As we lower the gearing and the load becomes easier to move you will need to pedal more and more to get the same total amount of movement and, very importantly, you will need to pedal faster and faster if you want to move the load the same total distance in the same time as before. Billy will manage this because of his super fast legs but you will struggle as you loegs simply wont go fast enough. This is because Billy produces more power than you.
How does that apply to your bike and the road? Well, if you look at your R6 and my VTR1000 you’ll get a good idea. Your R6 has low torque (compared to the VTR) but more power. If we both sat side by side at the same speed (say 40mph) in a gear that meant both bikes were doing 4000rpm and whacked the throttle open the VTR would disappear into the distance while the R6 was still coughing and spluttering. Now, if we both sat side by side 40mph in what we considered the best gear to accelerate forward, the R6 would be revving much much higher and would be using much lower gearing than the VTR. As we whacked open the throttle the VTR would get an initial advantage due to the torque (Lance Armstrong just stood on the pedals) but very quickly the R6 would build up more and more engine revs (Billy pedalling like mad). The VTR would soon need to go for a higher gear as it would run out of revs at about 9000rpm. As soon as the higher gear is engaged the “load” is greater thus the rate of acceleration slows. The R6 on the other hand would rev on to 14000 before needing to change gear and increase the “load” so the VTR’s initial advantage would soon be lost. After a short while the R6 would simply reel in the VTR and go past it.
Does that help?
chilli said:
David,
That explains it perectly, thanks v much. So really the advantages of a TWIN or a more "torquey" bike over mine is the fact that gear changes are less frequent, and the revs are lower?
That explains it perectly, thanks v much. So really the advantages of a TWIN or a more "torquey" bike over mine is the fact that gear changes are less frequent, and the revs are lower?
Exactly that! For me, the instant ‘punch’ out of a corner (as Lance stands on the pedals) or the fact that I don’t have to ensure I am in exactly the right gear all the time are much more important than ultimate top speed or standing quarter mile times. Each to their own though!
Edited by black-k1 on Wednesday 6th September 09:19
Great explanations. I think I am not alone in sort of superficially understanding the difference between torque and power - I'm about 95% there, but have trouble grasping that final 5%. The way I understand it suggests that torque and power are nearly the same thing, since both are measurements of energy. In my simple mind it seems that power must be a mathematical factor of torque and revs, so is there a formula that gets you from one to the other ? 'Torque X Revs = Bhp' sounds far too easy though !
gr4 said:
Great explanations. I think I am not alone in sort of superficially understanding the difference between torque and power - I'm about 95% there, but have trouble grasping that final 5%. The way I understand it suggests that torque and power are nearly the same thing, since both are measurements of energy. In my simple mind it seems that power must be a mathematical factor of torque and revs, so is there a formula that gets you from one to the other ? 'Torque X Revs = Bhp' sounds far too easy though !
You're right. Power is simply torque per second. Thus and engine producing a constant torque output will double it's power output at double the revs.
gr4 said:
Great explanations. I think I am not alone in sort of superficially understanding the difference between torque and power - I'm about 95% there, but have trouble grasping that final 5%. The way I understand it suggests that torque and power are nearly the same thing, since both are measurements of energy. In my simple mind it seems that power must be a mathematical factor of torque and revs, so is there a formula that gets you from one to the other ? 'Torque X Revs = Bhp' sounds far too easy though !
That's exactly what it is. Torque is a turning force. Power is the rate at which work gets done. Work is the application of a force through a distance, so power is force * distance / time i.e. force * speed. For a rotating object speed would be rpm, hence force * rpm i.e. torque * rpm for an engine.
Steve.
Maybe I'm missing the obvious but isn't that what it does say?
Incidentally, the image was robbed from this page
www.carkeys.co.uk/features/technical/636.asp
Incidentally, the image was robbed from this page
www.carkeys.co.uk/features/technical/636.asp
rsvmilly said:
Maybe I'm missing the obvious but isn't that what it does say?
Incidentally, the image was robbed from this page
www.carkeys.co.uk/features/technical/636.asp
Incidentally, the image was robbed from this page
www.carkeys.co.uk/features/technical/636.asp
The image gives torque as lb/ft (pound over foot) where torque should be lbft (pound foot).
Good description though.
chilli said:
BliarsGoing said:
Understeer is when you hit the wall with the front wheel.
Oversteer is when you hit the wall with the back wheel.
BHP is how fast you hit the wall.
Torque is how far you take the wall with you.
HTH
Oversteer is when you hit the wall with the back wheel.
BHP is how fast you hit the wall.
Torque is how far you take the wall with you.
HTH
a slippery road covered in diesel diddnt help but this is a pic of the understeer problem
She's a bit battered up but has gone off to be fixed
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