Hi Don, It's certainly a pleasure to "meet" you. I have a 22ft. Chrysler sloop, mast head rig, with a 150 genoa bent onto a roller furling extrusion that fits over the forestay. I have a standard main. In air over 10 knots and close hauled, my forestay starts to "pulse". I have really cranked down on both stays, but it doesn't seem to help. The boat moves very well and points beautifully, but this "thumping" is annoying and only increased with wind speed. Any ideas?