Well thanks to a fellow bowhunter, I was convinced to do some experimenting with one of my recurves. The bow is a 45#, Shakespeare, Necedah from 1967. It has a 3 layer shedua tip overlays and in very good functional condition. That said, this gentleman made up a 10 strand, 450 bowstring for me to try. I know....I'm an old dacron curmudgeon but bear with me.
Prior to gettin the 450 string, I used a D97 on this bow for about 200+ shots with no ill effect.
I checked the tips after every round, and continue to do so. After I got the 450 string, I've shot about 200 more shots and the bow is doing very well.
What I noticed immediately was a very crisp shot process with little bow movement. I also noticed the string does have some elongation on release, as it shows on the limbs where I sprayed them with some gray paint. There seems to be an additional 1/2 to 3/4 inch travel from where the string rests at brace.
Since I have no electronic gadgets to measure and compare speed, I have only to gauge by feel and my point-on. With the dacron string my point on was 52 yards; with the 450 string it is a tad over 58 yards, using app 490 grain arrows; 2016 @ 28" with 125 grain tips. That's with split finger, corner of mouth, with back of thumb/hand against my cheek bone. The noise is no greater with the 450 than with my dacron...that was a surprise to me.
I don't have much invested in the bow so I figured it was worth the chance to see what effect, if any, the newer material would have. I'll keep at it and closely monitor the evidence.
At this point, just through shooting and bow behaviour, I don't see where it is any harder on the bow than the dacron was.
Now please understand. I'M NOT TELLING ANYONE TO DO THIS!!!!!
I am simply satisfying my own curiousity as to whether or not we are just supposing that the newer string material is overly harsh on older bows. Perhaps some will be, but so far I'm not seeing it with the 450 string. More to follow.