Ok then,sorry about the delay but events conspired against me completing the tests on the traces.
Just a warning before i start,this has turned into a much bigger piece than i first intended so apoligies at the begining!.
The traces used were made up with size 6 Fox semi-barbed hooks and Korda swivels,with 7 strand Drennen wire and Q.E.D.wire,both in 20lb breaking strain,to make the tests easier to do i left off the middle hook as the tests were to compare the crimp/spinning methods,two traces were made with each material and each method: standard crimping(once through the eye,and crimped with Drennen crimps)and larks head-spun/heated tag end as per Budgies diagrams(a few "practice"spins were done first to try the method first).All traces had tubing over the join as would be in use.
The force was applied by clamping the swivel/hook in a set off tapered jaws to prevent slip and stop the hook twisting/bending and affecting the results,the hook was also held by the barbed treble in such a way as to stop it rotating about the hookbend centre.
Ok, onto the results:
20lb 7-strand
crimped broke @ 22lb and 21lb
@ the hook crimp.
twisted broke @16.5lb and 15.4lb
@the hook crimp
20lb Q.E.D
crimped broke @ 25lb and 24.4lb.
@ mid-trace.
twisted broke @ 25.2lb and 25lb.
@ mid-trace.
Just before the Q.E.D broke a period of plastic deformation took place, where the trace stretched without the measured force increasing, during which time the strands started to break one at a time, whereas the 7-strand reached its peak strain and snapped!.
The results seem to suggest that crimping is stronger than twisting, however the 7-strand may not be suited to this method of construction (or my ham-fisted efforts are well below that needed for this method!!) however in real terms the traces are still breaking at a higher value than the "standard" 15lb mainline used for piking.What is interesting is WHERE the traces broke, this has raised questions for me as to the "margin of safety" of the material in this breaking strain, I like the way that the Q.E.D. failed, IMO there is more of a chance of landing a fish if the trace has become damaged during the fight as the stress-point is away from the hook/trace junction which will be flexing as the fish moves. This will mean that my stock of 20lb 7-strand will be binned in favour of a higher strain for future use and the Q.E.D. will probably be the "trace of choice" for snaggy swims.
I think that in future my traces will be a hybrid:the larks head i like so i will use this with crimps (like you Graham), for a belt and braces aproach.