I thought some of you mechanical wizs might like this.
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Reminds me of a quote I tried to live my working (engineering) life byâŚ
Normal people believe that if it ainât broke, donât
fix it.
Engineers believe that if it ainât broke, it doesnât have enough features yet.
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Personally I am quite fascinated by planetary gears and the way they can be implemented in tracked vehicles for turning and such.
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What did we do before Lego technix? Mrs W is a smart cookie but I wholeheartedly failed explaining the difference between torque and horsepower until i showed her the Lego technix utube thing.
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There was a stiff link in the chainâŚ
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Have you got a link to that? Iâd like to see it as well.
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What bugged me was it was going the wrong way around.
Ill have a look.
It wont link for some reason but its âhorsepower V Torque explained by Legoâ on utube
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Horsepower is how hard you pull your spanner (hehe). Torque is the length of your spanner
Breakfast viewing, today. Lego is such a useful thing! I watched the part about what a Newton-metre is, and lb-ft, twice. I get the idea of a pound of force applied at the end of a one foot bar; straightforward enough because I can imagine the weight of a pound in my hand. I had to look up what one Newton feels like. Apparently, and somewhat conveniently, itâs about the force applied by gravity while holding a medium-sized apple.
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Newton is also a measure of tension.
Indeed. Does that bit of physics have any application in our motorcycles? Assuming youâre not towing a trailer. 
I like Ryan and FortNineâs explanation. (The fist two âtricksâ in that vidoe are interesting too, IMO.)
Newton is the SI unit for specifying physical âforceâ, doesnât matter what kind of force.
A force moving in a circle (or any path) is travelling a distance and doing âworkâ. This work is transferring energy, and 1N of force moving 1m transfers 1J (Joule) of energy.
How fast you transfer enegry is power, and 1J per second has itâs own SI unit name, a Watt.
Basically, for engines, power = torque x RPM x scale factor for units involved.
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Thats why you will always see power and torque cross eachother on a dyno graph. I think its 5250 rpm from memory where they cross. I might be a bit out but its always the same rpm.
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Interesting, although the maths was going a bit too quickly for me. I prefer to work in SI units as well but hey-ho. I donât think any of us are fooled by seeing just the peak figures, are we? I know they have the âooohâ factor but who doesnât look at the torque and power cureves off a dyno when theyâre published?
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And then you have to throw gearing into the mix as itâs torque at the wheel that matters rather than torque at the crank.
An electric bike/car has massively greater torque than an IC one, but the advantage is not as great as it looks because it only has a single gear.
Horsepower is more important than torque in a bike because of the lack of mass it has to move around, but torque is more important than horsepower in a truck.
Put a 200hp 1 litre bike engine in a car and itâs hopeless because of the lack of torque.
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Dead right.
