Hi Ron, I have a skyhawk 2 stroke engine that goes 25+ on a Huffy Good Vibrations mountainbike that has front shocks! Last April 2007 I had been researching motorized bikes on the internet when I saw one locked up and for sale across from Swami's Cafe! The engine was new and I bought it for 400. After a year and a half the vibration is too much so it needs attention to detail, like remounting the engine. I've been researching 4 stroke engines and I'm aiming to buy one of them soon! seahaggy