How does a motorbike central stand provide mechanical advantage?

[Alec98]

Homework Statement:: How does the central stand of this guy's motorbike enable him to lift it with little effort?
https://youtu.be/QjhqcrGvlvg
Relevant Equations:: I understand he succeeds by using mechanical advantage having good leverage from the engineering in the stand.

Could anyone help me work out a resonable explanation of how that leverage works? It makes no sense to me...

 

[Merlin3189]

He looks a beefy guy, so may weigh about half as much as the bike.
If the stand is nearer the back than the bike CoG, as appears to be the case because the rear wheel lifts, then the pivot is the front wheel and there is some lever mechanical advantage.
When the stand is on the floor, are the bike support leg and the foot lever at different angles to the ground? Looks maybe. Then the foot may be further (horizontally) from the pivot point (on the ground), than the support attachment point to the bike. Again some MA.
Doesn't look like he does this, but a lighter person could increase his force by accelerating his body upwards sharply as he steps on the foot lever.
Ditto he could apply a little horizontal torque on the handle bar and top box as he steps on.

If you can find a sideview so that we can estimate a few measurements maybe we could quantify that a bit.

 

[Alec98]

Really thank you, I probably couldn't have wished for a more complete answer. I don't really need to obtain specifically the real measurements in this case, it was mainly a matter of understanding how the leverage produces the MA and now i get it 100%!

 

[berkeman]

I've lifted plenty of pretty heavy streetbikes using their centerstands. I think the keys are that you don't have to lift the weight of the bike very high (and not the whole weight -- the front wheel stays on the ground), the pivot for the centerstand is very close to the COG for the bike (just slightly behind it), and the lever arm of the lifting stand compared to the lifting distance gives you a good mechanical advantage.

Even with all of that though, it does take a lot of your weight and some lifting with your right hand in opposition to your right foot pressing down in order to make the centerstand transition work.

Do you have any friends with such motorcycles that you could ask for a demo and to try it? I switched to sportbikes/superbikes many years ago, so even if you are close to Silicon Valley, California, I'm not able to help you try it out.

 

[Lnewqban]

There is also the pushing of the bike back simultaneously as you keep the stand pressed against the surface in order to obtain enough friction.
The vertical distance is small and the stand acts more like a cam than like a lever: basically the bike is "encouraged" by the rider to jump over the stand.
Once the bike is over the vertical position of pivot-contact point line, it falls down a little into a self-locked position.
Dismounting the bike from there requires only a pushing forward effort.