2003 GTX 6.5m for Hyper

[Allan Cross]

Hi Sukhdev,

My new investment this week is a GTX 6.5m, any thoughts or ideas or anything I should be aware of when rigging it for the Hyper.
I hope i wont be dissapointed with the performance of the sail for my needs.

Cheers Allan

[sukhdev]

Hi Alan,

I was out an hour ago in a storm with the GTX 7.5 on the exocet turbo75 while Ben our repair guy was out on the Hyper with GTX 6.5. Our collective experience:
- don't be afraid to go well over specs for downhaul and outhaul for slippery top end.
- get the leech well loose for the hyper.
- get some serious tension on the middle battens.
- take advantage of the low dry weight of the sail & get a lightweight mast and boom and you will end up with a very light rig, lower in weight than most race sails.

have fun, its a combo we use alot here. If I have the time I'll take a picture of Ben's GTX 6.5 tomorrow and post it here to show our preferred setup.

[Allan Cross]

Hi Sukhdev,

Yes the pic would be helpful regarding your preffered rigging guide on the GTX, tell me what masts are you using for the sail as it sets on a 430cm mast. Im not a great fan of the Fibresnap masts and they are not longer imported into the uk. But at present I am using a Fibrespar 75% carbon mast

[sukhdev]

nice thing about the gtx is that its not mast fussy, we've stuck all kinds of masts into it; was sailing the 7.5 with an ancient CK95 in it yesterday (dont ask why!). In fact we feel it sets better on the 75% powerex than on the 100%. It will be interesting to benchmark on the Ignition 75% once they arrive. Pictures below are of Ben's rig. He's 65kg and planes ridiculously early on the 6.5 with a SB Hyper...note the adjustable outhaul. Mast is a pryde wave mast of all things...hope the pictures help. The sail is as set for use on the hyper, on a heavier & less efficent board the downhaul will be just a tiny bit less.

Top view: note foil is twisty up top, downhauled to give clean lean leading edge down to boom area.

         

Windward view: sail has built in depth in the midsection (boom area), so if you underdownhaul the midsection will have a massive curve; great for low end but at the expense of control/top speed.Set as in the picture the sail gives a good balance of low end power and top end speed.

         




Leeward view: shows degree of looseness, 1st panel has lots, 2nd panel about a third to midway, 3rd panel has looseness in the first 25%. Once loaded up on the water, the leech firms and twists up beautifully.

         

[Allan Cross]

Hi Sukhdev,

Thanks for the pics, It looks like I rigged mine similar, however havent had the oportunity to sail it as yet.

Cheers Allan

[<Juri Munkki>]

My apologies for digging up an old subject:

Based on the "2003 GTX not being mast-fussy" and the Gaastra site saying pretty much the same thing, I ordered an 2003 model 8.5 GTX for use with my Hypersonic 96. I'll be using a North Viper 75/490 on it. I also have a North XC60 (60% carbon) 490 and a slightly older non-drop shape 510 that I can experiment with.

As far as I can remember, it's my first ever Gaastra sail, so it will be interesting. I've been using Norths for 15 years now... Of course using the "wrong" mast isn't really fair to the sail, but the price of the sail was too good to pass up.

Has anyone used North masts with Gaastra GTX sails? If so, how did it work?

Speaking of odd mast choices, I used to use a Neil Pryde C60/460 mast with a North Sails IQ+3 for a few years. It's what I had when I did my best ever speed on that sail (GPS-measured). I bought that 60% 490 North later and I think the sail rigged a bit better on it, but it wasn't any faster and not all that different to sail either.

[<Raimonds>]

Hi Juri,

I haven't sailed GTX with North mast myself but I am recalling that on Gaastra forum someone said that Echo or similar nocam sail was working beautifully with Viper mast. So the bend should be more or less ok.

My only concern would be the smaller diameter of North masts for Gaastra sails with cams. Will the original Gaastra cams hold on the North mast?

Anyway - GTX are truely awesome sails. Very light and very fast and slipery with huge range (I get 8knots till 22knots from my 9.8). If you will experience probs with masts, maybe you can sell North and get a second hand Fiberspar? In May anything is possible  

Aloha,
Raimonds

[<Raimonds>]

Hi Juri,

I haven't sailed GTX with North mast myself but I am recalling that on Gaastra forum someone said that Echo or similar nocam sail was working beautifully with Viper mast. So the bend should be more or less ok.

My only concern would be the smaller diameter of North masts for Gaastra sails with cams. Will the original Gaastra cams hold on the North mast?

Anyway - GTX are truely awesome sails. Very light and very fast and slipery with huge range (I get 8knots till 22knots from my 9.8). If you will experience probs with masts, maybe you can sell North and get a second hand Fiberspar? In May anything is possible  

Aloha,
Raimonds

[<Juri Munkki>]

I got the sail & mast today. To my surprise, I got a 2004 GTX instead of a 2003. I guess they ran out of stock and since they had promised me a GTX, they sent me what they had.

Beautiful engineering... I love that antiwrinkle stuff on the panels and the pocket in the mast protector and all the other little details. Rigging was quite OK too even though I'm not a fan of pushing the mast through the cambers. Only having two cambers makes things easy enough.

The sail seems to set very nicely on a North Viper75/490. I have to wait until Saturday to get a boom for this rig (my old boom only goes to 235 cm and the 2004 model requires 239). Still, given my years of experience of looking at cambered sails, I'm very pleased with the way the top twists and what the draft shape was like.

The cambers were very easy to rotate. It's possible that they are ever so slightly looser on the Viper than on the intended Ignition. I'll only know if stability is affected if there's a problem with stability. I can tell that rotation will be very easy.

I'm glad I ended up getting the 2004 (for the going price of a 2003!), because as far as I know, many of the nice little details that I mention above were new for 2004.

[<Juri Munkki>]

I have sailed the 8.5 GTX twice so far. It's working very well with the North mast.

I haven't tried it on other masts, so I can't compare.

I made some camber spacers out of silicone tube to tighten up the mast sleeve. Rotation is still very easy and the mast sleeve is much smoother.