Our 89' Burley would toss the timing chain when we were beginners, we were not smooth back then, boy that thing would flex, rode it for years. When you hit a bump, it would bounce 13 times. Moved up to a Cannondale, much stiffer everywhere, your behind really noticed. It was good for a gear everywhere, and when you hit a bump, it bounced a couple of times. This bike was very stiff, almost over the top, a mid 90's bike. We moved back to steel in 07', bought a Co-Motion Supremo, and there are no more bumps in the road. Comfort first for us. Tubing materials today are simply amazing. Combined weigh under 300lbs