Rick, The strains (loads) on the forstay are much greater (very technical term - MUCH greater) as the foil its drum line and sail are all available to be literally flailed about on the forestay as it is being furled. You will experience at some time in the future, the entire furler/sail combo wildly flogging about - this is amplified if your headstay is not tight enough (good case for a powerful backstay adjuster or in the case of the 15 - tight shrouds). I have found over the years of installing a couple (LOL) of FF's that - #1. the foil itself likes to be completely straight and flat. We used to drill a 3/16 hole in each end of the foil and stretch them on a fence in the hot sun for a couple of days - truckers hitches to tension them. #2. the headstay needs to be somewhat tighter than you may be used to with hanked on sails. The tighter forestay will take some of the movement out of the upper end of the forestay. Make sure the upper bearing is riding on the swedge body fitting (fork or eye) as you do not want the bearing piece to abrade the wire itself. NFIW but the CDI Flexible Furler is a great piece of equipment - Do they still have that very interesting warranty coverage claim? The one about the vehicle driving over the foil? I am not a big fan of furlers but when I bite the bullet - CDI will get my money. GaryO M-17 # 316a Team Geezer Racing...Old and In the Way **************Biggest Grammy Award surprises of all time on AOL Music. (http://music.aol.com/grammys/pictures/never-won-a-grammy?NCID=aolcmp00300000... 48)