Well this is sh*tty. I spent like 30 minutes typing a response when this thread first started, and I thought i posted it but i guess i didnt???
*sighs*
The way that I learned brakeless G-Turns is by going as slow as you possibly can and popping your rear end up, turning your bars and pumping. The motion of popping the rear end up and turning into the circle will naturally pump the bike.
It really only took me a day to start doing them in 360's. But bear in mind that i've been doing g-turn's by locking the brakes and spinning since i started riding flat a year ago. Which, by the way...i CANNOT do anymore! Everytime I try to lock my brakes and pivot i fly over the bars
The key to learning the trick is by controlling the rear end of the bike (keeping it in the air) by balance ...and by using the front wheel/bars as a learning aid. You'll notice that in this trick, like many others (hang 5s etc) that you can pop the bike or keep it popped by turning your wheel inward. As you start to get the hang of this, it will vastly help you progress through the trick. It feels like a cheat at first, but you'll eventually learn to do it without any wheel turning aid
Infact, you get a pretty nice balance/stability by turning and keeping your body on the outside of the bike. By doing this, your front pegs will be pointed more towards the ground and the sky as opposed to parallel with the ground.
body posture is key. VERY IMPORTANT : The flats of your knuckles should be facing YOUR FACE! You want to keep your wrists as straight and pointed forward as much as possible! you DO NOT want your knuckles facing downward towards the ground as they naturally do when you grip the handlebars. By having your hands positioned in this manner, you will get at least twice as much balance within the trick.
You'll notice in my videos that im very far forward. Your face should be pointed down towards the ground and you should be looking at a spot on the ground roughly 6-10 inches ahead of the front wheel. If you cant manage this, then you'll be falling back onto the ground every single try. Falling forward is a good thing! And its a very easy trick to bail from, despite what it looks. After a day of attempting it you'll be a pro
You do not want to lock your elbows. Keep them slightly bent, but once you start the trick they want to be RIGID.
As for foot placement....it doesn't really matter which foot is forward in regards to which way you turn. I turn to the left and my left foot is forward...which is probably backwards
But works fine for me!
Old vid of g-turns with me using brakes:
Recent video with some good G-turns: (at 56s you'll see my head is like 2 + feet AHEAD of the front wheel!!! I cant express enough...LEAN FORWARD!!!)
A g-turn with a pivot/scuff:
Im happy to help with any questions or further pointers on the trick...im brain dead right now so i cant thunk no more!