I was too lazy to bust out all of my string making equipment recently to make a new recurve bowstring and then . . . a special offer popped up from the 60X string and cable people, so I ordered a new string from them. It came right away (third day in the mail!) and was a very nicely made bowstring. It measured, as expected, 3/8ʺ less than the length ordered, but they are very clear that they make their bowstrings to AMO specifications, which means that recurve bowstrings are measured when under 100 pounds of tension. (Which I am sure would get the length to exactly what was ordered.)
My question is this. Have any of you ever put a tension meter on the string of a strung bow? I would love to see what the tension was on a normal bow to see how 100 lb compares.
Additional questions might be:
- How does brace height affect string tension?
2. How does draw weight affect string tension? (I have drawn a lot of bows and the higher the draw weight, the higher the string tension, but that is just the direction of the change, not an indicator of the quantity.
3. Does twisting of the bow string affect tension?
I can design the experiments and actually pull them off . . . but I do not have handheld tension meter (say 0-200#) to make the measurements. They seem to be a bit pricey on the Internet, with the cheapest versions being sold for sailboat rigging.
Anyone interested? (I’ll pay for the data and/or article.) Anyone ever heard of such measurements being made?
Postscript I have run afoul of this with commercially made Dacron strings, suited for very light drawing bows. These bowstrings were always too short, possibly because the light drawing bows could not come up to anything near the 100# of tension they were measured under. Strings can be shortened by twisting but not lengthened. When I make my own strings I can adjust the build length to make sure this doesn’t happen … but when you need a dozen strings … ouch.