Riding up walls ... without additional tools? Does that even work? Of course it does! During a wallie, you quickly pop the board sideways against a wall. In order to learn the wallie, however, it's better to find an obstacle with a gentler angle. That way you can develop a feel for it. The steeper the wall, the more difficult the wallie. You can even build your own obstacle – it's not that hard. Simply take a plate of wood or metal and lean it against a wall or a bike stand and you're ready to dork around!
BS WALLIE - STANCE: REGULAR
Place your feet on the board as if you want to do an ollie. Crouching down a little always comes in handy.
The most important thing is shifting your weight properly. In order to make sure that the board comes along for the wallie, you have to shift your weight onto the back foot and lean back with your whole body. At the same time, the feet get busy. Instead of the regular pop motion, the back foot pushes the board against the wall in the direction of travel. The nose travels upwards because you're leaning back. You're now right in the middle of the wallie. This whole motion requires a little bit of practice.
Now the board has reached the highest point of the trick. Stretch out the front leg so that the board gets back into the horizontal. The body is now parallel above the board again.
Almost done! Stay above the board, land, and enjoy the successful trick.