I'm making a split tail mainsheet for my Albacore using a Sta Set main and spectra legs. The instructions I've read online say to sew the bite in the legs to the end of the core, but I'm wondering whether I could thin the Sta Set core and weave the spectra legs through a few inches of the core. See attached practice pictures.
Good question... last time I spliced line, I was using a 'fid kit' on yacht braid, which tells ya I've been around since dinosaurs roamed the earth. But I did good work, and never failed to whip the throat of an eye splice, lol. Dunno if ya have to do that with Spectra or other modern lines, but it looked beautiful on the yacht braid.
Could you link to those? The pictures don't make it totally clear what (or rather how) you're trying to do.
I have never made a split-end mainsheet, but if I had to, I'd do it in one of the different ways:
1) Get a double-core rope, and stitch and whip at the end of the cover
2) Taper a ("normal", single-core) Dyneema-core rope, make an eye splice at the end, and attach the bridle part with another eye splice
3) Find a rope with equal-stretch core and cover, take the core out and lead the core and the cover to opposite sides of the boat to form the bridle.
Anyway, the second picture looks ok; the problem (well, one of them) is that Sta-Set is a relatively low-tech rope, and connecting its core with anything Dyneema-ish creates a discontinuity. You need to stitch the red and the blue together fairly tightly.