Rig Tune

[layline]

Ok, I know alot of this is very top secret stuff but I was curious if anyone has started to mess with the setup at all.  I have played with pre-bend and rig tension but it is so hard to tell what is working because of the rare times you actually get to line up with another boat in the same breeze and water. 

I know the Hyde sails like a paticualar rake and pre-bend but after sailing with Quantum's this past weekend I noticed they didn't quite like the same setup.  I had a chance to glance at the North's this weekend and they too looked very smooth.  The kite was huge and Jason was not lacking on pace.  If everybody is sailing roughly the same setup than most of then I would have most of the answers but if someone is trying something different it would intersting to see and possbily learn from the results. 

My last question is has anyone actually published a tuning guide or is it still a work in progress?

[Matt Rowlinson]

I don' t think this will be news--but the Hydes like prebend--we sail with about 4", spreaders max aft, & very loose lowers.  Rake the mast until you get that balanced viper helm & you're good to go.

But enough about us--how did the North & Quantum sails look?  who was fast?

Matt. Rowlinson CAN 70

[Jason Weisberg]

Well I think all the setups vary to how the sails are shaped.  When I sailed with the hydes at the end of the season I raced the boat extremely loose.  Looser than most.  That said it also depends on how much your total crew weight is.  That is a big factor on the rig setup.  With the North test sails that I used this past weekend the rig setup was totally different than what I was used to.  The North kite is probably better suited for heavier crews because it is Max in area.  Ched proctor from North is in process of writing a tuning guide.

[layline]

We only sailed the Quantum's on Saturday for a race and half before the rig broke.  I would have to say after sailing the Hyde's the Quantum's look totally differnent and are very smooth.  The setup was a bit different though.  This is why I asked the question.  As I thought no real answers have come out.  Mast rake, rig tension, forestay length all still up in the air.

[Justin Scott]

The Viper mast is designed to be sailed like a modern high performance rig. In light air you need a fair amount of pre-bend (3-5"). In medium air and medium heavy, you set up with less pre-bend and let the rig respond to puffs. In really big breeze you add back tension again

The position of the chain plates and the fairly extreme rake of the spreaders mean that adding rig tension will immediately add a lot of prebend. It also means that as a puff hits and adds pressure to the rig and tensions the windward upper, the mast will bend and depower in the puffs.

In order to get the best from the rig, the main needs to be cut with a reletively deep draft and enough luff curve. Otherwise you will be fighting the rig. Either your main will be ineffective in the puffs or you will be fighting the prebend through tightening the lowers (and making the rig more fragile downwind ....snap crackle pop!).

The southern hemisphere sailors discovered this first when they started putting softer masts and deeper mains on dinghies in the 90s and were dominant. Everyone else quickly followed suit. You look at the rig tension of the top 5-0-5 guys when they go out in the big stuff...its amazing....there is not much rig tension at all.

Viper is much lighter than a conventional keelboat. At the same time it is heavier than a dinghy.

I sail with about 36 on my uppers in light air. 32-34 in everything else until it gets to 18+ then I crank up to 38. It is important not to have too much lower tension. In light air I have just enough so that mast does not sag to leeward but allows a lot of fore and aft pre bend (they're very soft).