The forward mast BEND
My boat has the same slight forward bend from the upper spreader to the mast top. This can be seen when sighting up the front of the mast. The mast itself is raked back so that a weight suspended from the mainsail halyard hangs about 2-3 inches behind the past at the gooseneck, which is good. The bend in the mast has been there since day one. It looks to be maybe an inch or two, but it's hard to tell for sure. I haven't been able to get a straight edge on it, Ha Ha. It is not noticeable unless I sight straight up the mast from the front or rear. It almost looks like an optical illusion, but I don't think it is. Until now, I haven't heard of any other C310 with this condition. I wonder how many people would even notice? It's hard to imagine what is causing the bend. The shroulds should not be appling any fore or aft pressure on the mast, only side force. I would think that if the forestay or backstay was too short, then the whole mast would just tilt, not bend. Why just at the upper spreader? I usually have the fore and aft stay's set loose anyway, so they should not be contributing to the bend. I've done a lot of tuning on the mast, starting at ground zero, and have not been able to totally eliminate the bend. I have worked through the standard tuning procedures, settling on shroud tensions at 10-12% of wire strength. I have the forward and aft lowers tight, but not as tight as the uppers. The forward lowers are tighter than the aft lowers. If the lower shrouds are set just taught, they seem to have too much slack under sail, so I have them around 8% of wire strength. Checking under sail shows the shrouds just starting to go slack in about 15-18 knots of wind. I normally keep the backstay (and forestay) on the loose side. I have a backstay adjuster, that when tightened up hard does seem to reduce slightly, or even eliminate the bend in the mast . At the dock, the weight on the main halyard is about 4-5 inches behind the gooseneck with the backstay on tight. So rake is increased an inch or two. I've done a lot of research on this issue and have not found a logical reason for the bend, especially because of the location it's at. Also because of the location, I have not found a way to apply a correction. The lowers have a limited effect on the bend because they apply force at the lower speaders, not the upper speaders where the bend starts. I did solicit an opinion from Brion Toss, the rigger, at his website. His only idea was that maybe the mast itself had been bent at some point before it was stepped. I finaly decided to just get used to it. It doesn't seem to have any practical effect, and hasn't gotten any worse. I wish it wasn't there, but it seems to be fine.
