If you add weight to arrows(not the point or nock end) with tubes or the "Rope trick " do you have to retune your setup/bow?
I think if you were borderline stiff you could possibly see a difference. I have never had problem or noticed a difference though.
Rob
Theoretically it could change the spine some because you are adding some type of material inside the shaft, but I don't think there are many of us good enough shots to detect the slight spine change it would cause. Of the two I would go with rope just because it is a softer material so again theoretically it wouldn't stiffen the shaft hardly at all if any and I have heard lots of negative things about using weight tubes.
I had to. Made my arrows act weaker.
I have used weight tubes in the past and NOT had to retune but, like said above, if you are near the edge, you may well have to do a bit of retuning.
Bisch