I see there was a thread about dyneema and bend radius recently. We put that issue completely to bed for 6mm and smaller lines back last fall (because the loop is twice strength, a bend ratio of slightly better than 1:1 is full strength). But John F continues to insist there is some sort of scale effect that changes/reduces it in larger diameters. The industry does not agree with him, but it has been an 'unresolved' question.
So, to put it all finally to bed, I am (just organized today) hiring an independent test lab to break 15 samples at different bend rations and throat ratios with 12mm heat set line. They need to build a jig to easily change the bend ratios, and I need to order the line and splice up the samples, so it will probably be about 5 weeks before I get results back.
BUT . . . the head of this testing lab is a true rope/line expert - the technical director of the Cordage Institute in addition to doing state of the art industrial cordage (they are working on NASA parachute lines today) since 1974.
I was talking with his son, who has been with him since 1978. When I explained why I was doing the testing he said in passing:
"Not sure who your “expert” (which is how I referred to John F when I explained the situation) is on Dyneema, we fabricate large diameter dyneema lines everyday that are used in the Overhead Lifting industry and based on our and Cortland’s extensive testing we have no problem in recommending a 1:1 D/d configuration in the eye. We generally have not seen any significant reduction in strength going as low as 1:1."
In any case, I will report back on results when we get them.