Added Shok TL length change spine dynamics?

[docholidayy]

HI guys, Newbie here, first post!

I'm building a arrow for a new V3x 29 I picked up this year. 28.5 DL 70#.

Using archers advantage software it says a VAP 28.5" ctc with 36gr on the back and 175 on front (125 head & 50 Shok TL Outsert) hits optimal (460gr total weight)

My question is will the added length of outset sitting past the carbon (1" from what I read) change those numbers and affect the spine and kick it out of alignment?

Thanks for any feed back!

 

[Billy Goat]

Not enough to matter.


Keep in mind that shaft length is going to stick out past your riser a fair amount.

 

[Arctic Hunter]

In my experience it will. But not a lot. But you can always cut 1/4” at a time off the back of a bare shaft if it acts a little weak.

 

[docholidayy]

Not enough to matter.


Keep in mind that shaft length is going to stick out past your riser a fair amount.

That did cross my mind. What are the downsides to that?

 

[Billy Goat]

That did cross my mind. What are the downsides to that?

I think it's less forgiving, get a bunch of arrow out past your rest and it's easier for it to get pointed the wrong way with torque.

It also means you need to use a heavier spine than you might otherwise need. That's not always a downside, just part of it.

I have most all my shafts cut about the Berger hole. It just works well for me.

 

[Syng2015]

That did cross my mind. What are the downsides to that?

Weird anecdote. I have a few 340 spine Easton Bowhunters that are 31" CTC and I have a ~30" draw. They stick out far enough that I can poke the target before I shoot. They are also very weak spined for my 72#. And the good ones shoot lights out.

There's probably something about the first dynamic bend and harmonics that I can't measure, but can observe, at play here. There's nodes along the arrow and the location and amplitude of the wave as it passes over the rest is a critical value. This combination is a rare fluke.

Arrows whip, not just bend. The bend travels up and down the arrow, effectively the point snakes its way through the air in all directions based on the input from the bow. As long as the input and bend are the same, the flight should be the same. The alternative is to make the height as low as possible, so that variation is minimized.

This can easily work the opposite for you, and can wreak havoc with broadhead flight. But it does help to explain why arrow length matters beyond the static spine rating.