I put an air shock on the Quest hopping to eliminate any noise, and the original spring shock seemed to bottom out occasionally. I didn't expect the 20% increase in performance. Went on a 50+ mile ride today with some good climbs, the air shock stiffened the frame and I could climb 10-12% grades with two clicks left on shifter and not struggle. I can now start uphill with very little problem. My fatigue level is half what it was using the mechanical spring shock. Anyone that wants better performance from their Quest while keeping the comfort level should invest in an air shock before clip-in pedals. New name for Quest is Pocket Rocket.