Had a Yamaha BWS 50 do this to me when working as a private postman in Nottingham maybe 20-25 years ago. Pulled up at house and let bike fall onto its sidestand at which point it picked itself back upright and rode off down the road until it hit a kerb square on and was launched 6ft up in the air landing on someones garden hedge with me running after it. The look on the bus drivers face parked up down the road on a fag break was priceless
