I have bought an oldish ( I believe) 2nd hand HSM Fusion sail, 5.2 m. I didn't know it was a wave sail, neither did I know much about wave sails and the difference with freeride sails, but the condition was excellent.

My intention was to use it as a regular free-ride sail, .but I immediately realized that it responded very differently ( and unpleasantly!) from the free-ride sails I was accustomed to.

The main difference is that this sail has a very tight leech and the top remains stiff even with the maximum downhaul, unlike freeride sails which can be adjusted for more or less stiffness on the top by playing with the downhaul. The downhaul does absolutely nothing to looseb the top.

In fact I kept being annoyingly catapulted forward all the time, with winds gusting to 15-20 knts. This never happened with even larger freeride sails in the same conditions.

I wonder if it is because of the specific design of wave sails, which require a different handling technique

For one thing, from what I read on the Web, wave sails, unlike freeride sails, are specifically designed with the C.O.E. on the top sail, which subjects the sailor to a leverage force from the top, hence to catapults, without the proper technique. .

The sail is also very, very heavy, no doubt because of its material, designed for the punishing wind conditions of wave sailing, in addition to its thick battens.

One thing I have to mention is that the Fusion is designed for a 430 cm mast, but I use it with a 460 cm mast, because it has a vario top. Does this perhaps affect the curve of the mast, resulting in a tight leech?

My be somebody can comment on this

Thanks

Francone

Early '90's?
Still should twist with a correct 430 mast, lots of downhaul.
Almost every 1988 or newer sail will show loose leach with enough downhaul, sometimes more than spec.
Shorter mast is softer, allowing twist.
Longer mast is usually stiffer, tightening the entire leech.

Normal advantage of wave sail over freeride is more durable, quicker jibing, allows for using slightly smaller sizing, since more material above the boom, and lighter wind waterstarts per size.
Of course, specific designs vary and comparisons can be adjusted.

Also, for 72 kg riders, 15-20 knots is within parameters for 5.2 sails. Gusts of 22 knots should be really powered.
That's providing your board is less than 120 liters and you are using both straps.

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LeeD said..
Early '90's?
Still should twist with a correct 430 mast, lots of downhaul.
Almost every 1988 or newer sail will show loose leach with enough downhaul, sometimes more than spec.
Shorter mast is softer, allowing twist.
Longer mast is usually stiffer, tightening the entire leech.

Thanks LeeD
I tried it again on a 430 cm mast, M.F. ext 12-14 cm as per specs.Slight improvement, but still little twisting, if at all. No comparison with my other HSM 8 m freeride sail. That has a lot more twist at the top.
I really begin to think that this stiffness in the Fusion wave sail is due to its design, with the C.O.E at the top .

Francone

Wrong mast + inexperienced sailor.

Twist is not a necessity.
For sure, pre twist, 1983-1990, I was happy in 15-22 wind with any 5.0, wave or 3 cam. At 150 lbs.
Now, at 160 lbs., max downhaul and baggy outhaul, same wind, still 95 liter boards.
Now if wind gusts up to 27, give me a twist head sail newer than 1995.....talking 5.0 sizing.
If wind insists on staying 14-18, no higher, I'll choose a 1986 Gaastra Race foil 3 cam.

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Francone said..


One thing I have to mention is that the Fusion is designed for a 430 cm mast, but I use it with a 460 cm mast, because it has a vario top. Does this perhaps affect the curve of the mast, resulting in a tight leech?

That could be the cause of your troubles. The mast is too stiff for the sail, it wont twist off and release, and give you the problems you stated.
My experience on a different sail but same symptoms - I have an Ezzy 4.5m Panther and the recommended mast is 370 bottom sections and 400 top section. I initially used it on a 400 mast and the sail was very stiff, powerful in lighter winds a bit unpleasant on stronger winds as it didnt twist off. Buying the shorter bottom section reduced the mast length by 15cm and made a big difference.

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Francone said..

LeeD said..
Early '90's?
Still should twist with a correct 430 mast, lots of downhaul.
Almost every 1988 or newer sail will show loose leach with enough downhaul, sometimes more than spec.
Shorter mast is softer, allowing twist.
Longer mast is usually stiffer, tightening the entire leech.

Thanks LeeD
I tried it again on a 430 cm mast, M.F. ext 12-14 cm as per specs.Slight improvement, but still little twisting, if at all. No comparison with my other HSM 8 m freeride sail. That has a lot more twist at the top.
I really begin to think that this stiffness in the Fusion wave sail is due to its design, with the C.O.E at the top .

Francone

OK, just read that, so guess it is the sail, sounds old from what LeeD said.

Remember, Hot Superfreaks don't show any loose leech, yet have wide wind ranges.

HSM use flex top, not whatever random stuff the OP is using. Also this isn't a Superfreak and regular HSM sails look like anything else on the correct mast.
My QU4Ds rig loose in the top half and respond nothing like the OP is describing.

Fusions never rigged fully twisty, which is why in 1994, they introduced the one camber freeride with TONS of top twist. They were hesitant to make twist top sails until the following year, making them behind the 8 ball and maybe never recovering.
In the early '90's, they were very popular and was seen everywhere. By the late '90's, they were seldom seen. Spiderlock waves kept them afloat during the mid '90's.

Yep, you're right about these two things:
1. Your mast is longer and therefore stiffer than recommended.
2. HSM sails require flextop masts to work properly.

So in your case, the leech will stay tight, adding tension makes the sail flat yet stiff with very on off feeling. Plus it'll also be heavy during transitions.

Solution is to use a smaller than recommended mast or you can try a shorter top.

^^^ +1

What freeride sail BTW? Are you on a correctly rigged 10 y/o or less freeride sail? If you are, any early 1990's wave sail will feel awful - even if on the right mast. Then, having it on wrong mast and using it as your high wind sail, yeah rodeo ride.