I learnt this 2 days ago
I had ago on my friends high spec limey 320 and tryed it on that and somehow I did it first time.
But when I tryed it on my low spec t pro it feels ALOT different. So it could be your bike restricting you?
I can do it now but I did it by starting small, doing a small wheelie up it, holding the front brake, but then when you drop onto your back wheel, when you halfway down I transfer my body weight to a hop to the back wheel, and then pushing on the cranks to lift the bike up.
Hope this helps
