How Does The Lift Force Generated In This Action?

[mammalwong]

Does the swing arm actually rebounce with the aid of the engine? How does toni lift the bike to that height in terms of mechanical, body movement and physics?

[crazybond700]

Actually if you like take the steps appart its:

 

Compressing the swingarm and shock absorber

Timing of power of the engine

The body itself actually sort of jumps like you normally would without a bike (same story, compress, use muscles, without a bike you would use your arms aswell)

Knees are used to compress the rear, and to make as much as possible space to extent and to shift the bodyweight towards the top of the rock.

And he hits the fender/rear tyre with his behind when the rear tyre gets on top. Then he pulls hos body forward again. This way less weight has to be ''shot'' into the air.

Edited June 20, 2016 by crazybond700

[mammalwong]

But it looks like the suspension rebounce and the jumping of the rider's body could only generate 20 - 30% of the whole lift force at most to me.

How does the timing of the engine affects the lift in detail? Doesnt it only affects the forward force?

[mammalwong]

When somebody do a normal splatter which begins with the both wheel on the ground, I can still imagine the wheelie generates much up lift momentum to the center of mass to the bike. But this splatter begins with the front wheel already in air and he still can lift the bike over a meter 0_o

[crazybond700]

How high can pro basketbal players jump?

[mammalwong]

You do make a point. Btw does he pull up the bike with his ankle?

[ourian]

[mammalwong]

Wow, this really solves the question in my mind. So the rear tyre becomes a kicker itself.

Edited June 20, 2016 by mammalwong

[anotherfive]

Good explanation in the diagram. Makes more sense to me now as well.

[anotherfive]

I think the chain may play a part by trying to shorten along the top run as the clutch is released. Thereby pulling the rear wheel upwards.

[sectionone]

I bet there's a kicker hidden behind the log. When there's no kicker, he has more speed and does a upper body double pump to get that kind of lift.

[heffergm]

There's a kicker you can't see behind the log... you can see him roll up and then back down it 2-3 seconds into the video.

[mammalwong]

You are right, I never realize there is a kicker.

[mammalwong]

I think the chain may play a part by trying to shorten along the top run as the clutch is released. Thereby pulling the rear wheel upwards.

I guess only pulling the rear wheel downward do initiate a jump?

[mammalwong]

I do biketrial too, I just learnt my first pedal up last night lol.