Here we go. I dug up my small backyard and built a pumptrack. I used the small space i have but can keep up a surprising speed. Pumptracks can bee done on a bmx or mtb (i use a giant stp zero hardtail) and the idea is to not pedal but keep momentum by pumping over the bumps and through the turns. Good practice for any discipline of biking and it gives a good workout. Believe it or not but a few laps on my small pumptrack with no pedalling and your legs will start to burn. And it can be ridden by any level of rider. Mine is tame but if you have the room the sky is the limit.
Yeah sure is.
They had the first (2009) world championship over here in Australia in a backyard. I think it was in Canada last year. YouTube - PumpTrackWorlds2009