Just checked my tune

[Doug_K]

I recently switched string material on a couple of my bows, and was getting a somewhat erratic flight, so I decided to check my arrow tuning.

The bows are the 61# Leon Stewart and 63# ADM in my signature. Out of both, I've been shooting 14 strands of B55, shooting a 29" 400 spine carbon with 225 grains up front.

The new strings are 8 strands of Ultra Cam (big difference), and after some testing they shoot a 28" 350 spine carbon with 260 grains up front. No big problem for me, I'd prefer a heavier arrow, just need to buy more more 350 arrows.

Is such a change of spine normal when changing strings, or is there another factor i'm missing?

[katman]

Going from dacron to a skinny fastflight type string will change tune for sure, how much not sure, others will certainly chime in.

What he said^^^^^^^

Bisch

[AZ_Longbow]

Youe bow will tell you what it likes. Some times theres no big change, sometimes there is. Ive had a big change just by swaping string silencers on one bow, but on the next no change.

[Doug_K]

Ran the numbers through Stu's calculator and it appears it is normal.

Just for the hell of it I made one up for my 55# Bamabow and checked, it shoots the  400 spine/225 combo perfectly with the 8 strand FF string.