effective alternatives to horses and steam

for powering public transport, wind,

in the form of large kites, were seriously considered.

But now after two centuries of development,

we still don't have kite powered buses.

But we can do this.

The board flip.

Yes, the butter slide.

A nice fence for a grind.

Watch out for my post turn.

And then there's this.

The roll.

An airborne inverted spin.

Nice work.

See you next time.

That was an advanced version of a role.

A core kite surfing trick with plenty of variations.

Kite surfers can front roll, back roll, roll, and nose grab.

There are all sorts of ways of mixing it up.

And that wasn't one of them.

To perfect the right kind of airborne rotation for a kite

surfing role requires a mastery of angular momentum and lift

force.

Here's the roll 101.

As wind flows over a kite's wing-like shape,

it generates lift force, pulling him across the water.

On launch, he throws his body backwards,

generating just enough angular momentum

for a complete rotation.

To land, he steers his kite downwards and ahead of him.

This increases lift force in the direction of travel,

so he avoids sinking.

It is complicated stuff to deal with all at once,

so first, let's just practice using lift

force to get a little air.

OK, We've got that covered.

Now let's add some angular momentum for the roll.

I said, some.

I mean, he did get enough angular

momentum for one rotation.

But he didn't have time for two.

OK.

Let's work on the landing.

Now, can you remember which direction

we need to send that kite?

No, quite the opposite.

He actually aced the angular momentum,

But if you want to go in this direction,

like your board, and your kite is

steered down in this direction,

It's not going to happen.

OK.

Last chance.

Arguably worse.

Lift force in wrong direction,

Too much angular momentum.

Very sinky landing.