I'm considering building a (wooden) half pipe in my back yard for my son and me. He's riding a BMX, I'm thinking about getting a DJ bike (Specialized P3). I've found some plans online for a 8x27 halfpipe, but I'm wondering if that is not too narrow for a bike (we're both just starting out).
Anybody here actually built something like that themselves? What size? Any things I need to look out for?