Weight tubes in arrows? does it change spine?

[Elk Chaser]

I am working up arrows for a fall Elk hunt and I may be trying to go with a Carbon Tech Rhino .
only problem is that it does not weigh enough. so I just added 3 gpi weight tubes and now have the arrow at 460 gr with feathers , nock and inset so adding a 125 gr or 150 Silver flame broadhead will be close to 600 overall
Do the weight tubes change spine of the arrows these are flying great right now but have not tested with the weight tube installed.
Thanks Bill

[doctorbrady]

This brings into consideration the difference between static and dynamic spine.  There are a lot of folks here who know much more about it than I do, but here is my understanding...for the paper it's printed on   .
Adding weight tubes will not change the static spine of your arrow, however, it should attribute more of your bow's energy to the arrow which may slightly lessen the dynamic spine.  I have shot arrows with and without 3 gr/inch weight tubes and notice a minimal change when bare shafting arrows...but I always still check.  Hope this helps.

[Elk Chaser]

doctorbrady
I also found another source that stated the same thing that the dynamic spine decreases slightly

I just shot 10 thru paper and there fine, leaving a hole and 3 spines for feathers at 6 yards
Much appreciated.
Bill

[doctorbrady]

Bill,
Your welcome.  By the way, by the looks of your postscript you have too many nice bows to shoot at once.  Do you need me to put one or two of them to use for you?  

[Bill Kissner]

After experimenting with several different things to add weight to carbons it is my opinoin that the weight tubes changes the spine far less than anything else I tried. I really like the yellow (3gpi) tubes.