I'm 205lb and had the same problem with my rear Mavic Open Pro 32 spoke wheel, one that should be fine for my weight. The problem is that the heavier you are the higher the spoke tension has to be for the wheel to remain stable. From the builder the drive side spokes were set at about 100kgf. To stabilize it, I ended up having to raise the tension to around 125-130kgf. At any tension much lower, the non-drive side spokes wouldn't be tensioned enough and at least one would work itself loose in short order throwing the wheel out of true.
Gerd Schraner, author of the Art of Wheelbuilding, suggests that when setting the drive side tension, tighten the spokes so that the rim is pulled all the way over to the drive side, adjusting the non-drive side only as much as is necessary to true the wheel. Only then do you adjust the non-drive side to properly dish the wheel. Doing that ensures the non-drive side spokes are at their highest possible tension.
Last edited by Proximo; 08-23-07 at 10:12 PM.