Partner block newbie question.

[shadowboxer]

New Viper owner trying to figure out how to rig the line at the partner block. It looks like it is set up to have the line go from the cam cleat on the starboard side of the mast in front of mast to the block mounted on the port side and then back in front of mast to cam cleat. This would limit how much the mast pre bends forward but I have read about that I should be trying to keep the prebend and prevent mast from inverting at higher wind speeds, which would have the line going behind the mast and forcing it forward. Not sure how I should rig, also I have 3 plastic blocks that limit how much the mast goes forward.

[Justin Scott]

The line is sorta superfluous. It was intended as a replacement for mast chocks in front of the mast, but go for mast chocks, they are better and easier to adjust to constant settings.

I have a variety of different thicknesses and I know which combination works for my three mast tune settings. As a starting point, set up the pre-bend to your standard setting without any chocks. In my case that is 27 on the uppers, with about 2 1/2 -3" of prebend. Then put in mast chocks so it is snug but not forcing the mast back. For light air, take out a thin chock. This has the dual effect of (a) softer headstay for same mainsheet tension and (b) Slightly flatter mainsail lower down without using gnav.

Other than that the line is useful to put behind the mast in case Olaf's crew removes the headstay pin before you are ready.

[Dan Tucker]

New Viper owner trying to figure out how to rig the line at the partner block. It looks like it is set up to have the line go from the cam cleat on the starboard side of the mast in front of mast to the block mounted on the port side and then back in front of mast to cam cleat. This would limit how much the mast pre bends forward but I have read about that I should be trying to keep the prebend and prevent mast from inverting at higher wind speeds, which would have the line going behind the mast and forcing it forward. Not sure how I should rig, also I have 3 plastic blocks that limit how much the mast goes forward.

You have it right on how it is meant to be rigged, forward of the mast to limit bend down low. We (Rondar) don't want you to overstraighten the mast with excessive blocking or excessive lower tension. That can risk inversion and mast failure...

[Justin Scott]

I think limiting bend down low actually straightens the mast.....but Jeff will probably put me right.

Get chocks.

[Jeff Jones]

Justin is right.  That line is just another dysfunctional factory option that should be discarded.

If anything put it behind the mast as Justin mentioned.  Nice way to induce forestay sag in light air.  505s have a mast ram up control that has the same affect.

Get chocks, perfectly repeatable way to add forstay tension.  I don't believe the have any bearing on breaking the rig.

Justin, I only put you right when you are wrong.  This time tucker is wrong, but attribute that to him towing the company line. 

[Craig Walker]

Can someone point me to a good source for the chocks?

[Doug Mroz]

I ordered mine from APS and they work fine. http://www.apsltd.com/c-6097-viper-640-mast-and-rigging-accessories.aspx

[Justin Scott]

Justin is right. 

Good Grief.

[Drew Harper]

IME the JCD chocks don't fit well and are stupid expensive. I use the Ronstan chocks.

http://www.ronstan.com/marine/product.asp?ProdNo=PNP200

[Glenn Vanheel]

How much are those drew?

[Justin Scott]

Porter chock set is the best. Milled angle to match angle of the mast. Curvature is exactly right. Width fits snugly in the partners. The milled aft chock has a base plate, so you can slide it in before the mast goes up and it prevents any of the chocks coming out once sailing.

Sadly they are no longer available. Not sure why someone doesn't replicate these commercially. Fantastic.

But the wife's bread board and 15 minutes with a router works well.

[Drew Harper]

How much are those drew?

$39 at Mauri Pro