Originally Posted by thutchings
I hope he does, LOL. Hes known on here as Daniel Boone. I just dont want to bog him down with all the questions all the time. Thanks for the info.
Listen carefully to him. He knows what he's talking about and has learned from some great archers. And don't worry about bogging him down by asking him archery questions. It seems to be something he likes talking about.
The 55/75 number refers to the spine of the arrow. Spine is how much an arrow bends when it's shot. (technically: frequency and amplitude of oscillation). Static spine is a measure of how much an arrow bends when a 1.94 pound weight is hung on a arrow that spans a distance of 28". Dynamic spine is a lot more complicated and there is no single measurement for it. The complicating factor is that there is not always a good relationship between dynamic and static spine.
Different manufacturers list the spine of their arrows differently. Some list the actual measurement, some use an arbitrary number, some like GT use a number related to the draw weight it is intended for.
Spine isn't quite rocket science, but it's pretty close. Fortunately for new archers, you don't have to understand it completely. Compound bows will shoot most carbon arrow spines pretty well. There is an optimal spine for every setup, and the closer you get to that, the better. But you won't realize the benefits of perfect spine until you get a lot better.
For now, just go by what DB tells you.