VXR 31.5" Tuning Tips

[targetpanic]

Did you say 70v mod, all I can find is 80s?

Billy Goat has a TRX 36

 

[JBahr]

I ended up having to use the most extreme combination on the top and 2nd most extreme on the bottom shifting the cam left on both to tune mine. Bare shaft, three and four fletch all shoot bullet holes now. It's pretty easy to do with a press and paper tuner in my garage, but it would have been a royal pain in the A$$ to have it done in a shop.

 

[Rrobason]

JBahr Am I reading that correctly that you had one set on top and a different thickness on the bottom?

 

[Billy Goat]

JBahr Am I reading that correctly that you had one set on top and a different thickness on the bottom?

Yes. Pretty common. Shimmed in the same direction, but not same amount of shim.

 

[JBahr]

So mine were actually left of center on the top and right of center on the bottom. Middle pair on the top, 2 most extreme pair on the bottom. Took me a while to figure out the right combo and I am still playing with them. The Gas strings seem to be a little more inconsistent than originally thought. They are the only variable other than the ambient conditions. Please PM me if I can help in any other way, happy to discuss my findings over the phone.

 

[Derek abrahamson]

I was also having the same problem over and over i've swapped top hats a million times and was this close to getting rid of the bow, I moved my rest back towards me about .25 to .5" and it seemed to clean alot of it up...still working it out but that seemed to help more than moving my top hats (again)

 

[Reburn]

I was also having the same problem over and over i've swapped top hats a million times and was this close to getting rid of the bow, I moved my rest back towards me about .25 to .5" and it seemed to clean alot of it up...still working it out but that seemed to help more than moving my top hats (again)

That would indicate form problems. Most likely torquing the grip. By moving your rest back you essentially started torque tuning the bow to make it more forgiving. Also not to patronize but make sure your using several different arrows when you paper tune. One arrow may not be happy for what ever reason. If I shoot 5 arrows through paper and 3 are bullets and one is a touch left and the other a touch right that is an arrow problem that needs nock tuning. Not a bow tuning problem.

 

[Holocene]

Late to the conversation, but wanted to add an idea.

Besides potential form issues, another thing to watch is bow balance. If you have an imbalance in your bow such as a sidebar or quiver weighting one side without a proper counterbalance, that could cause tears that are hard to chase.

I've tuned 3 Mathews bows with top hats so far at my home shop, and when tuning a new VXR today ran into this issue. I put the bow in spec and fired a bare shaft and fletched shaft -- perfect bullet hole at 6 yards both of them.

Then, I put my backbar on the bow and shot again without the quiver -- tear! And tear again! I removed the stab and was back to bullet holes. Put the stab AND quiver on, bullet holes.

This imbalance and tear were specific to my setup, but really opened my eyes to a tuning situation that in hindsight seems so obvious, but was easy for me to overlook.

Suggestion for anyone with inexplicable tears -- make sure your bow setup is balanced correctly, leading to that good form folks above talk about.