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sboardcrazy said..Francone said..
Hi
I just bought a brand new RRD X-TRA 7 m freeride sail to use with my Gun Sails 460 cm 75% cc mast. I had for some years.
The mast is cc, 25 ICMS
I rigged the sail on my backyard, awaiting warmer weather and there is something odd with the rotation, as explained below.
First, here is how I rigged it
Outhaul: the specs call for 203 cm +/- boom extension. With this extension, I pull the sail end to about 5 cm from the boom clew. According to the common instructions, and my previous experience this outhaul tension should OK because the sail can be pushed down by hand to almost touch the boom, indicating that there is enough shape for lighter winds, if needed.
With this outhaul, the sail is however hard to rotate by itself. I can do it only by hand. It rotates better ( by hand) if I give more tension on the outhaul, but then it loses shape , becoming considerably flatter, i.e. the opposite problem: too flat for light winds.
D/haul: I pull the d/haul until the sail foot is about two fingers thickness from the MF pulley and the leech becomes loose until the 1st batten above the boom. I don't know if this is too much d/haul. but if I d/haul less, the sail becomes even harder to rotate, even by hand..
I wonder if the rotation problem can be corrected by adjusting the batten's tension. One thing that struck me when I first lay the sail on the turf before tensioning outhaul and downhaul is that the batten protrude about 2 cm behind the mast. Either they are too long or they have perhaps to to be adjusted. Would this help the rotation?
Thanks for the comments
Francone
Do the mast specs suit the sail?
This is the whole point. As I said in my post ,the Gun Sails mast specs are : ICMS 25, constant curve, 460 cm , 75% carbon, but there is absolutely no info from the RRD site about the mast specs required to match their sail.. The guy of the store I bought the sail knew that I already had a mast. If the sail was supposed to match a mast with some specific specs, he would have told me, but he didn't. So I supposed it was OK.
I know , matching mast and sail is the ideal solution, but very few people do it,. There might be some trade-off in using a different mast from another manufacturer, but, if people do it, I assume that in most cases there is no major draw-back.
Francone
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Mark _australia said..
I think now we might need to define "easy rotation".
If the leech is loose all the way down and the batten above the boom is level with the front of the mast it all sounds OK. Yes there is a slight curve mismatch but not much.
Francone this sail is designed for 20kn fully powered freeride. Do you have that much wind and it still won't rotate pully powered and with a bit of a pump?
No insult but if you're used to an old windsurfer sail or a wavesail set too flat from learning u may not be used to how a rigid deep-draft freeride needs to pop around the mast?
Thank you Mark and you all
for analyzing the problem, in an attempt to find the cause and a possibly a solution.
No , I havent't taken out the sail on the water, yet. I only deployed it on the courtyard. The wind was at times gusty, but definitely far from 20 kn .
This is really the first new , late technology sail I ever bought. My battle horse has been so far a 6.5 m NP Garda sail from the 2000's, a bit spent but enough for me in light winds . The Gardas , just like others I had, did, however, rotate much more easily with the least wind and/or by popping the sail.. I guess it was also because the luff pocket was comfortably large., whereas in my new RRD the mast fits rather tightly in the luff. especially towards the top. I really have to work it in by hand rather laboriously.
If, as you say, the sail is designed for 20 kn winds fully powered, in order to rotate properly, then the problem is more with my expectations than with the sail itself . Unfortunately, 20 kn winds happen very rarely here. It is mostly in 12-15 kn. I would hope that rotating the sail by pushing it with the hand or pumping is not a major draw-back.
Leaving the rotation issue aside, in the hope that the wind (or my hands!) will take care of it, the only issue I'm faced is that I cannot really trim the sail for light winds ( more shape) because to do so, I'd have to reduce the outhaul, but then the battens will move further back and the rotation will be even more difficult. ( I cannot compensate with more down/haul, because , as explained, it is already set at the maximum ( 1st batten above the boom).
The best is to try it out on the water. In the meantime, I'll pay a visit to the store and ask them to rig the sail on my mast or another mast to see if there is a difference.
Thanks for your suggestions
Francone