After digging deep into my current sail trim manual last Friday night, here’s what I found: a) lateral bend is real and it can be tuned into a fractional rig with swept-back spreaders b) like fore-and-aft bend, lateral bend occurs near the MIDDLE of the mast. The point up near the masthead where the forestay and uppers are attached is not supposed to move (much) c) vang tension opens the leech by pushing the boom and the middle of the mast forward and to windward. As the middle of the mast bows forward, the masthead moves backward and down, compensating for the downward pull on the boom. However, this only happens if the mid-mast is not too stiff d) in heavy air, both the middle and top of the mast can be bent to leeward. From behind, the mast ends up looking like an "S". This compound bend flattens the middle of the main and simultaneously opens the upper leech e) when racing, standing rig tension can be adjusted for the prevailing wind conditions before leaving the dock to enhance the effectiveness of the running rigging Based on my current rig settings, this means my lower shrouds are too tight, the uppers aren’t tight enough and the mast may need more rake (I took some out when I first adjusted the rig a year ago) Those discoveries would explain the loose leeward uppers when going upwind and the inability to open the leech by increasing vang tension (masthead too far forward and mid-mast too stiff). So, I guess it’s time to get Loos and go readjust the rig. *sigh* At least I’ve learned something new and I've got some time to experiment with it...the sailing season is closed for the summer. I’m also looking forward to Don's chart and manual...mine has great drawings but it’s not an easy read. Peter H23 "Raven"