Which Spine Rip TKO’s

[mww982]

Ordered the Elite Omnia and was playing around with archers advantage with my current arrow setup and adding Nockturnal lighted nocks to the equation. Adding the Nocturnal nock changes my spine from being being slightly weak to too stiff. Without the Nockturnals the spine is optimal. I’m not sure if I should stick with the 350 spine or bump up to 300’s if using lighted nocks.

Arrow Spec:
27”
50 grain collar
125 point

Bow Spec
65 lbs. Draw weight
28” Draw Length

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[Bump79]

I would go 350. You could always go 330 or 340 in a different manufacturer

 

[OR Archer]

Is the middle one supposed to be a 300? Adding a lighted nock to your current arrows wouldn’t put you as “too stiff”. You’re only adding about 10gr. I would stick with what you have. It’ll tune just fine.

 

[Mighty Mouse]

There's no reason to think lighted nocks would necessitate switching from 350 to 300 spine. Adding weight to the rear of the arrow makes dynamic spine stiffer, not weaker. But the extra 10-15 gr of a lighted nock is unlikely to noticeablely influence dynamic spine one way or the other anyway.

Your AA results seem a little fishy. Your screenshots show speed predictions of:

• 350 spine #1: 285 fps @ 446 gr
• 300 spine: 289 fps @ 447 gr
• 350 spine #2: 285 fps @ 462 gr

Speed is staying flat or increasing slightly as arrow weight increases, which is not what happens in reality. Seems like there's some other input parameter being changed between each iteration of the spine calculator...maybe IBO speed, let off percentage, weight on string. All of those bow-related parameters will affect the dynamic spine calculation to some degree.

 

[mww982]

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[mww982]

There's no reason to think lighted nocks would necessitate switching from 350 to 300 spine. Adding weight to the rear of the arrow makes dynamic spine stiffer, not weaker. But the extra 10-15 gr of a lighted nock is unlikely to noticeablely influence dynamic spine one way or the other anyway.

Your AA results seem a little fishy. Your screenshots show speed predictions of:

• 350 spine #1: 285 fps @ 446 gr
• 300 spine: 289 fps @ 447 gr
• 350 spine #2: 285 fps @ 462 gr

Speed is staying flat or increasing slightly as arrow weight increases, which is not what happens in reality. Seems like there's some other input parameter being changed between each iteration of the spine calculator...maybe IBO speed, let off percentage, weight on string. All of those bow-related parameters will affect the dynamic spine calculation to some degree.

The only parameters changed was the arrow configuration. So I’m not sure what’s going on there with AA. Dropped the point down to 100 grains to see and that may be a starting point but it’s dropping my FOC to under 12% per AA. However Q Spine shows the FOC over 14% but doesn’t take the nock weight into consideration. I’m trying to keep my FOC in the 12-15% range.

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[Mighty Mouse]

The only parameters changed was the arrow configuration. So I’m not sure what’s going on there with AA. Dropped the point down to 100 grains to see and that may be a starting point but it’s dropping my FOC to under 12% per AA. However Q Spine shows the FOC over 14% but doesn’t take the nock weight into consideration. I’m trying to keep my FOC in the 12-15% range.

Sent from my iPhone using Tapatalk Pro

qSpine does account for nock weight in its FOC (and spine) calculation. Scroll to the bottom of the "Configure Arrow" screen and you can enter whatever nock weight you want.


Back to the original question, you're overthinking this and putting too much stock in spine/FOC calculators. The effect of a little extra nock weight on spine/FOC isn't worth worrying about and definitely doesn't warrant changing arrows.

 

[mww982]

qSpine does account for nock weight in its FOC (and spine) calculation. Scroll to the bottom of the "Configure Arrow" screen and you can enter whatever nock weight you want.
View attachment 477542

Back to the original question, you're overthinking this and putting too much stock in spine/FOC calculators. The effect of a little extra nock weight on spine/FOC isn't worth worrying about and definitely doesn't warrant changing arrows.

Forgot to scroll!!!

Figured 350 would be fine, just wanted a second opinion. I'm not really interested in changing arrows unless I go back to a standard diameter arrow.