My experience with bikes is that 250 miles is about right for re-truing wheels. Sounds like youre riding on street like we have here in Oakland....Total ****. The wheels sound fine but have you tried messing with the tire pressures? take a couple off the front and it could soften the jolting. Also what about a larger tire like the schwable big ben 50c. In fact i have a pair i took off my izip dash i could sell you for cheap. There the class 3 black/reflex versions. Let me know..