May I ask some more advice? I’m replacing Blue Moon’s standing rigging and was surprised to see it is Dyform, and listed as such in the original owners manual. I have no plans to race and plenty of things to spend the extra £400 or so on, but before I specify standard wire I thought I should ask if I’m missing something. Does anyone know why what is primarily a cruising boat came with Dyform rigging?

Many thanks

Peter

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All I can tell you is that our 335 has had 1x19 wire says from new which have been ok for 8000 miles or so and that Dyform was fathomable in the late 1990s.

I don’t have the manual for the 335 to hand but I am fairly sure it specifies 1x19 for the rig

Thanks Martin that'll do for me, rare opportunities to spend less money shouldn't be wasted!

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Hi Peter, just be aware that Dyform rigging is significantly stronger than standard rigging (they are both 1x19 strand) the dyforming process compresses the wire and makes it a smaller diameter so it's strength is similar to the next size up. if you have say 7mm Dyform rigging, you'll want to use 8mm standard rigging to retain the same or similar strength. The difference in strength is around 30~40% higher. As you noted it was/is mainly used on race boats where they could get the same strength for thinner wire, thus saving parasitic drag, but it is also heavier than the same size standard rigging. (around 10%). Drag probably being more of an issue that weight aloft for a racer is probably what makes it popular. (becomes more of an issue as apparent windspeed increases, drag increasing exponentially as speed increases, weight aloft stays the same and becomes less of an issue in rising winds.)😀

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Thanks Martin. Low windage and low stretch were the benefits I knew about. It does of course make sense that if you put the two together you get a beefier wire for the same diameter, but I hadn't made the connection the other way so thanks for drawing my attention to it. I will check with Barry the rigger and have a whole new price/fashion conversation with him!

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I’ve got dyform rigging which I specified when replacing the same around 10 years ago. I think it’s stronger which I thought necessary as I do race but also the rig is pretty big with no effective backstay (apart from bending the mast) so all the rig loads are on the shrouds. But I’m not an expert !

Thanks all. For the record, and future owners facing the same question, a quick conversation with Barry the rigger and I'm staying with Dyform. Closer inspection showed that to change to the next size up in 1x19 would need to change the mast terminals and perhaps chainplates too, quickly outweighing any cost saving on the wire.

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