I weigh about 245lbs and have ridden with the Mavic A319 rim on the back and Velocity Dyads and Synergys on the front without unexpected problems. I cross railroad tracks 16 times a day for my commute. After 2 years (8000 miles +), the Mavic developed cracks around the spoke eyelets but there was no catastrophic failure. Rims are going to wear out, especially at my weight. If you are a clydesdale like myself, I would not recommend the Velocity Synergy OC for the rear. I have had cracks develop with less than 1000 miles on two of these rims. I'm not saying the Synergy OCs are bad rims, they just can't handle my weight on the rear wheel. The front wheels have had no problems; still going strong. Just my experiences. Hope this helps