[Mr. X]

This raises an important point: you can use much thicker Dyneema wishbones with sharkfins than with notches. Not sure if that is true of the new RA mini-fins, which are quite small (although I suspect it is true of the Dessault mini-fins that Glowworm & Podge recently got). The RA wishbones are much thinner than those used by Bill McIntyre, and I suspect Pastor. I'm guessing Mishu never bothered filing the grooves of his spear to handle Dyneema (per the excellent link above). However, I had trouble with wishbones last year that turned out to be due to not having the rubber lengths quite even on both sides (16mm rubber probably slides into place with use if uneven but the 20mm rubber did not) - causing the wishbone to be dragged through the groove of my RA spear each time it was fired.

A washer sounds like it might cut dyneema (& rubber) unlike a round bead or the pear-shaped RA nylon toggles. I must make an effort to rig my wishbones like Pastor this year - cheaper & more convenient.