Originally Posted by WDSchock
.....how does one control the mainsail shape if one can not change the Pre bend of the mast.........
The only large impact shape adjustment we can make is with the outhaul. It is pretty effective to alter the curve front to back, since the foot is loose from the boom, and we use it to match the genoa after it has been trimmed.. The vang and travelers can be used too, but more subtly.
Since our boat was originally designed to have a furling main, I suspect the 135 genoa (you can fly a 150 as well), was designed to do most of the work. It certainly does. In fact, deep downwind, we are often tempted to reef or entirely furl the main just to get it out of the way. We are very pleased with performance overall and mainsail shape is not usually a concern.