I'm not positive, but as best as I can recall I believe the Nexus hubs have max RIDER weight limitations that fall somewhere between 190lbs - 250lbs (a quick check yielded a range of weights for the 3, 7 & 8 speed models). I'm not sure if the weight limitation pertains to the hub brakes or the hub itself.
Edit: Added "Rider" to answer next question.
Last edited by TandemGeek; 07-14-07 at 06:45 AM.