Ed,

I'm no expert but I noticed one thing about too much spreader sweep coupled with tension. I found that 2" on my Inter was messing up my leach and causing the sail to s-curve when sheeting hard--more so when I used any DH. More than likely I need a new sail--but the one I have has to last til next year. I am now somwhere around 1.5 to 1.75 and my leach now stands up right, sail flattens out nicely with DH with little S-Curve except when I really wail on the main sheet. Now I am experimenting to find the right tension settings for the diamonds to see what works best.



Whatever the right settings, I think other posts nailed it on the head---match the prebend (mast) to get the best sail shape. Use the settings others are using as a ballpark as each sail and mast is different, even if its one design.



As for mast rotation, I have found no difference between more prebend or less, I think rig tension makes the biggest difference.



Regards,

Don S.

I20