So, a some what delayed follow up to my original post regarding the lack of pointing ability of t my SO 37. The new headsail produced significantly better results than I would of thought, that combined with a different rig setting and maximum tension on the backstay have gotten the boat very close to what I had expected. As mentioned by a couple of other members the 125% has a better sheeting angle and is better suited to our local wind conditions., that combined with an additional 3 seconds per mile added to our rating has helped. We depower early and try to keep the boat as flat as possible. My next project is to convert to an adjustable backstay, I have all the parts necessary just need to get some help and a couple of days t do the conversion. more to come !
Hi Johannesburg, I bought some gear to convert to an adjustable backstay but haven’t made the conversion yet. my plan was to add a block where the twin wires converge ( Removing them) and use a non stretch synthetic line to go from starboard up to the new block and down to a cascading block setup with 9-1 purchase. Was your setup similar ? Thanks
But with some variation. I used a 70 mm Selden block attached to the existing wire backstay, with a Selden rigging toggle between. The line is 6 mm dyneema. Then two additional cascade blocks, and a 4:1 purchase at deck level. So in total 4*2*2*2 = 32:1 nominal purchase. It feels just like the right amount. I preferred the 4:1 purchase at deck level to 6:1, since it makes for a slimmer setup. These are the components:
Seldén PBB70 Single block (attached to backstay) Seldén toggle 3/8 Seldén PBB60 Single block (2nd cascade) Seldén PBB50 Single block (3rd cascade) Seldén BBB40 Fiddle block (4:1, top) Seldén PBB50 Fiddle block with becket and cam (4:1, bottom) 6 mm Dyneema 8 mm double braid polyester sheet line (for the 4:1)
It did the dyneema splicing myself and it was fairly easy. The trickiest part is to measure the correct lengths. Use the old backstay for comparison. Unfortunately I cannot find my notes with the lengths I used...