I'm looking at some bamboo shafts,the seller says they are spined with a 28in spine tester.here is the question,I shoot 50-55 spine woodies witch are spined with 26inch tester,would the bamboo be weaker or stiffer spine? isn't 28inch used for alum. and carbon? thanks Burt

If he is using a 28" spine tester you want to order a weaker spine, by 5-10#

Some numbers for reference..

2016 .531  53# measured at 28"
    .435  59/60#       at 26"

2018 .464  60#          at 28"
    .375  68#          at 26"

Also, they say bambo/cane shafts are more forgiving in spine because they are a continous taper.

thank-you for the reference..Burt

Bamboo seems to be flexible with spine it seems. When I get mine I usually go 10# heavier than my Woodies and put some extra weight, like 20gr. up front if needed. I shoot a 60# r/d longbow @ 31" and am shooting 75-80 spine with 145 gr. up front and they fly great. I also have some that I did an internal footing with 75 gr, insert and 125 heads that fly just as well, so they are very spine tolerant.
Denny

Thanks Denny,I'm shooting hill style bows and draw 28inchs my arrows are POC and 29 bop 57lb bow 50-55 spine 160grn point,so if I go 55-60 I should be all set.(I hope) Burt

Check to be sure you guys aren't hung up on semantics.

For instance: is he using a spine tester for a 28" arrow or is he using a spine tester with supports set at 28" apart?
I'd ask how far apart the supports are on his tester. That should tell if the two of you are actually talking the same thing or different things.

Guy