I guess another question I have is this. I shoot rear 9.5" back tapered douglas firs. Ive also used 9" back tapered POC. Of course I used both types of wood in parallel shafts as well. When I changed over from parallels to tapered, both very well known shaft makers told me that the spine differences between parallel and tapered shafts, was so slight it would be insignificant, and that it was a very high pecentage chance, that I should order the exact spine shafts id been using in parallels, and they would very likely end up being the same length, as the parallel shafts in tuning them out. I found out that in making that size of back taper, 25-30 gr worth of wood is removed.....yet they said no spine changes would be necessary. I tested extensively, and I found out that they knew what they were talking about after all. Think about that, when thinking about these wraps changing dynamic spine..how can it be so, when the back taper effects spine so little? That taper is 11/32"down to 5/16".