Mark, Everyone I have ever talked to concerning belly boards always experienced a nose pitch up attitude. While on final I have to apply forward stick pressure to keep the nose down. This results in slower speed with a low nose attitude for great visibility on final. Also, I have never heard of anyone mounting the belly board to the main spar. I think if you do this you will once again be a pioneer and will have to report your flight characteristics as a comparison to the rest of us. Here is the link to my belly board web page: http://www.flykr2s.com/bellyboard.html
Jones Mark Jones (N886MJ) Stevens Point, WI E-mail: flykr2s at charter.net Web: www.flykr2s.com