Thank you for the useful information.
I’m just trying find out the difference between what they are selling. When I go to the BCY site they love to tell you the recipe, but they won’t tell you how it tastes. I can read the descriptions from the manufacturer but I was wanting someone with experience to tell me what the actual difference is on the bow. Is A faster than B? Does Y last longer than Z. Is the super duper future stuff going to blow up my 2023 Chinese bow or do I need to learn Cantonese and call the manufacturer for a recommendation? Big Jim didn’t tell me when I bought it off his website if it’s fast flight compatible but it’s got honking big limb tips (looks reinforced to me) so I’m going to gamble. I ordered an X99 string from Mountain Muffler strings. If y’all hear a huge explosion and see a mushroom cloud down by the Gulf, you’ll know what happened.
There are only a few modern string materials used today. There is a SK 75 dyneema and a SK99 dyneema. The difference is the purity. The older 8125 and Dynaflight 97 is made of the SK75 dyneema. These are excellent materials. But over the years, the quality and purity has improved to the SK99 version which is about as high quality and purity as it is going to get. Brownell's version of the 8125 was called D75 and D75 thin.
Back in the late 90's when 8125 came out as well as D75/D75 thin, the problem archers had with these materials was it would creep (permanent stretch) in high heat locations so they started blending these materials with a little vectran to make more heat stable strings. As for myself, I have built a boat load of string with 8125 and D75/D75 thin and never had any issues with creep. When BCY blended the 8125 with vectran, they called it 452x and Brownell did the same and called there blended version, Excel. I have built a lot of string out of Excel as well and it was a really good material.
Today, since the dyneema is now the SK99 version, the BCY blended version is called X99 and is 80% dyneema and 20% vectran and they still have the 452x. Brownell has a blended dyneema/vectan version, but I don't know what the ratio is.
Dyneema is light, has good stretch which gives it shock absorbing properties. (Stretch is where a material elongates but returns to its original length.)-(Creep is permanent stretch). Dyneema has a very long and predictable life cycle. Dyneema is quiet, durable and fast. I find dyneema to be stable and dependable.
Vectran is heavy, has no stretch. Makes for a hard shot. Vetran is porous and can absorb a lot of wax making it heavy and slow. Vectran is a shorter life material and its life cycle is unpredictable. But vectran is very stable and when blended with dyneema makes a very good stable and dependable string.
My favorite material today is BCY Mercury which is an unblended 100% SK99 dyneema small diameter material. It is easy to build with, settles quickly and is very stable. It is quick and quiet and has a long-life cycle. The small strand diameter allows for a really nice and round string that stacks together really well. By changing the number of strands by a couple of strands, the small diameter strand diameter is great for making a string that fits into the cam groove very nicely, depending on the diameter size of the end serving being used. Depending on the center serving diameter size, you can get a string that has a really good nock fit also.
For trad bows, I would tend to stay with a 100% unblended dyneema material like 8125, Dynaflight 97, Mercury. It would make for a soft shot that is easy on the limbs and limb tips. Brownell's Rampage is also a great choice.
