I have just put on a new set of Americas’s Best strings/cable. My lower cam has been marked since I purchased my Z7 to have an indicator if I get any string stretch or cam rotation. Everything is set up perfectly and the cam marks line up perfect with the new set on. I am paper tuning with a bare shaft at 4-6 feet and getting a nock low tear, about a full inch or more. The only way I can get this down to about 1/4 inch nock low tear is by raising my D-loop up a full inch above parallel. I am using a Trophy Taker Pronghorn drop away. This is the exact same set up I have used for 4 years with no problems and never had this problem before. Everything is set up exactly as it was before when I was getting bullet hole while paper tuning.
The reason I changed strings/cable was they were 4 years old and I was getting continual D-loop and peep rotation the last two months.
I have done all the work and tuning on my bows for years and have never had this nock low issue when my up/down centershot was correct. I have already tried twisting the buss cable up and then back down to change the cam rotation while keeping it within the cam timing circle. I have also tried changing the rest timing. No success!
The nock fits the serving very well. I’m getting the same results with multiple arrows…all that were just fine before changing out the strings and cable. I have talked to America’s Best Bow Strings. Their tech person cannot figure out what is going on. I called Trophy Taker, one person told me to increase the amount of time the rest is contacting the arrow and another said just the opposite. But so far, adjusting the timing of the rest has not produced any changes. I have talked to two pro shooters who are friends of mine. Both are not sure what is the issue but suggested continued adjustments to the rest timing to see if I can find a sweet spot.
Pretty confused…first time in many, many years I could not get a bow tuned (and I use to work in a bow shop)…and of course it is mine!
Rotate the nock 1/8th turn at a time to see if the tear changes. If there is a definite stiff side to the spine, it can have a significant affect on bare shaft flight depending how it is oriented to the string path.