Yes, I do bareshaft tune. The weight of the tubes was very similar to the nylon cord rope (3/16") that I was using. The bareshaft flight did not change at all for me. The only thing with the cord was that it was moving forward and getting very tight inside the shaft. I would think it would through off the FOC and the deflection of the arrow over time. All the inside pressure that I was getting over time concerned me. The tubes stay put though, so I think the 1 dollar a piece price tag maybe worth it. I would think they are reusable also.

The carbons are finicky thought to bareshaft tune. I have to really pay attention to brace and nock point settings.

The total arrow weights of the carbons with the tubes and the 190 grain grizzly come to 670 grains, with 24% FOC.