Excuse me sportscarpat. I'm dreaming: I see that you're not playing and are very serious. Your current frame and wheels can handle the 420cc, then start a century club in which members do 100mph to join. Maybe you can find a younger rider with experience racing bicycles and motorized bicycles. I believe you would be within the margins of safety if you do this once and don't keep pushing your luck with repeated 100mph runs. I see Whizzers souped up doing 80 plus mph. This would be a good selling point for the Sportsman 200 on Steroids: This is an exact factory production of the motorized bicycle that ran at 100mph. Thankyou sportsmanpat.