I started out with increasing my rig tension to see if I could induce prebend but only had limited success. I was able to get about an inch or maybe a little more with the mast step in its original location. I decided to make an adjustable step for the mast stub and thereby tilting the lower hinge plate forward and aft. By setting up the mast with only the rear pin in the hinge I'm able to get varying amounts of prebend by chocking the mast step forward and aft.
The interesting thing is that I've set up for vang sheeting with a 20:1 set up and this really helps to get a good amount of bend if I chock the mast stub back about an inch and a half. What this does is allows the front of the hinge to open and close about a 16th of an inch which really lets the lower mast bend nicely. I'm able to now get over bend "speed wrinkles" just as they are described in the North Sails tuning guide.
I got some sailing in last week with a breeze about 15 kn with some gusts up to 20 kn. I had experienced crew and with the nice bend in the mast and the new vang set up we were able to de-power the sail and get really nice performance considering the conditions. We did, however, get really wet from spray on the up wind leg.
Now the downwind leg was some serious fun. We were planing like crazy and the surfing was really exhilarating. My friend commented that it was like having a 500 hp motor when a wind gust hit.
KC