Transition…the most import part of the half pipe. The transition is the curved section of the ramp that goes from the flat bottom to the deck. Getting this right is crucial because a transition that is too steep or to mellow will not be fun to skate and your half pipe will turn into a giant lawn ornament. There is no equation for the perfect transition radius, the best thing to do is to draw out several different radii in full scale and select which one looks best to you. You could even draw and cut a few out on some cardboard and compare it to some local ramps or bowls in your area. I used computer software to design mine, but I’m still going to draw it out and think about it long and hard before I cut it out. Currently it’s a 7 foot radius. The radius should always be bigger than the height of the half pipe and the larger it gets the mellower it will be.