How to do a 50-50 Grind
The 50-50 grind is grinding with both trucks. Grinding is sliding on an edge, usually a curb, bench, or rail, using the trucks instead of the wheels or deck. If you use the deck that’s a slide. The name means half the grind is on each of the trucks.
50-50ing is the grind mostly used and is the one most of us learn to do first. Like a lot of tricks it starts out with an ollie. You need to be able land your ollies flat and be able to land your feet where you want them to be to be good at this trick.
You want to pick a good place to learn on. Most skate parks have ledges set up for it with metal edges. You can use rails too and even buy them. If you got curbs you can use them but most of them are rounded and don't work as well. Since your will be ollieing onto whatever you use pick something the right height. For starting out about 6 inches works. Waxing the edge helps you grind smoother and faster.
To start the trick you give yourself enough room to get going and do the ollie. Obviously, the faster you are going the further you will be grinding. When you get to the ledge ollie up onto it. You want to land with both trucks evenly on the ledge or rail. Bend your knees when you land and you should be landing it just like an ollie. Just like most tricks you want to stay level and balanced. At the end of the ledge or rail give the tail a small pop and land back on the ground aiming for all four wheels to land at the same time, just like an ollie.
If you want to get off the ledge before the end, like maybe it’s going into a wall and you don't want to kiss it, you just do a little ollie and pull to the side.