From the BCY website.Make from it what you will.
Question: If I reduce the number of strands to improve arrow speed, should I be concerned that the strength of the bow string is reduced and therefore dangerous?
Answer: With almost all modern materials used in the manufacture of bowstrings, the strength is well in excess of the maximum tension applied to the string. Consider this – A popular number of strands for Formula 8125 material is 18. The breaking strength of a single strand of Formula 8125 exceeds 100 lbs. Using 100 lbs as the criteria, the total strength of 18 strands is 1800 lbs. Of course when set up on a bow, the strands are split at the loops and a static load test shows that approximately 40% of the strength is lost at this point. This still leaves a breaking strength of over 1000 lbs.
It has been calculated that on a high poundage bow, say 75 – 80 lbs, it is possible to generate approximately 200 lbs total tension while drawing. Compare this to the breaking strength over 1000 lbs mentioned above and there is at least a 5 – 1 safety factor.
Reducing the number of strands is normally ratioed to the draw weight of the bow, therefore on lower poundage bows, the 5 – 1 safety factor will remain or perhaps increase.
With the newer, smaller diameter materials like 452, the single strand breaking strength is under 100 lbs but many more strands are used so at least a 5 – 1 safety factor is maintained.
Basically, using the manufacturers recommended number of strands x the breaking strength of the string, will assure you have a string with much more than adequate strength and if you decide to drop a couple of strands to increase speed, the strength of the finished string will still way exceed the maximum poundage generated by the bow.
Breaking strengths is rarely, if ever, the cause of a string failure. More likely causes are –
· condition of cam wheels (burrs)
· over twisting
· extremely tight serving/compressive failure
· type of release
· lack of string care and maintenance (lubrication)
· abrasion