Repack Rider and Wildwood

I didn't see this thread until today... Just last night I was talking about my experience with a Swing Bike... A friend had one- he was magic on that thing. He could do pretty much anything an ordinary person could do with the seat pivot all swingy- he had total control of it. We'd been out riding around- and I asked to ride the Swing Bike on the way back to his place. We're trucking around, I'm riding with one wheel on the curb and one on the road... I'm thinking I'm pretty damn good at this... and then we went downhill... I probably was fine for a quarter of the hill, and then it started wobbling, and once it started wobbling, I couldn't stop it and I face planted. Last damn time I'm ever getting on one of those death traps.