Stretch indeed!
There's abit of give in all sorts... if you release the luff line and stretch the sail.. you'll be surprised how far it will go.
Its more in the knots that hold all the bits together.. halyard, pole bow ropes...it all compress under load. We like to have the luff tight if a nice deep entry and then flatten the entry as required by easing some halyard - works good and took us a few solid races to get the luff length right...
This is why I have set up my boats with pre-bent pole, using static lines, and generally removing all the stretch I can from the systems. I want my luff stable so I can trim it. If it stretches 8cm, that is a huge change of shape to the luff of the spi which you can not control.
All my spis have had a 2mm or thicker spectra line in the luff, which I have set up as I want it on the beach. The cloth may stretch, but the luff line should take most of the load. With well aligned panels the luff should handle the loads gracefully. The number of panels and their layout is one of the large factors when trying to account for stretch. Few panels is cheaper, but many panels makes the spi more stable, prolongs lifetime of the sail and of course makes it more expensive. Personally, I think a gore larger than 7degrees for a panel in the luff is too wide and will have too many threads in the cloth off-axis to the loads for best performance. Much the same goes for the leech.
Personally I dont subscribe to the "ease to flatten" idea. I think it is much more important to sheet the spi and sail the proper way to get best VMG, and going the right way of course.
Platform weights are now 120kgs.
What is excluded from this weight. Sails? Boards? Rudders? Or is this ready to sail weight?
Pulling the Viper, Taipan and Blade up the ramp at the end of a sail it's Taipan, Viper, Blade in terms of 'easy'.
Why?
