Author Topic: Fletching and dynamic spine  (Read 2197 times)

0 Members and 2 Guests are viewing this topic.

Offline WhistlingBadger

  • Member
  • Posts: 1,728
  • Future Expert
Fletching and dynamic spine
« on: June 05, 2020, 10:08:10 pm »
Howdy, boys.  So, I'm playing around with some bare shafts again and have some 44#s flying well with 235gr heads.  Question:  Does adding fletching affect dynamic spine, and if so, which way?  I've been told before but can't remember.

Thanks!
T
Thomas
Lander, Wyoming
"The trail is the thing, not the end of the trail.
Travel too fast, and you miss all you are traveling for."
~Louis L'Amour

Offline Lehtis

  • Member
  • Posts: 347
Re: Fletching and dynamic spine
« Reply #1 on: June 06, 2020, 03:56:15 am »
One inch longer fletching equals 5 pounds stiffer arrow roughly... like going from 3" to 4" or 4" to 5"...

Offline WhistlingBadger

  • Member
  • Posts: 1,728
  • Future Expert
Re: Fletching and dynamic spine
« Reply #2 on: June 06, 2020, 08:35:01 am »
So a four inch fletched arrow will have a dynamic spine 20# stiffer than a bare shaft?  That's a pretty big difference!
Thomas
Lander, Wyoming
"The trail is the thing, not the end of the trail.
Travel too fast, and you miss all you are traveling for."
~Louis L'Amour

Offline Pat B

  • Administrator
  • Member
  • Posts: 37,617
Re: Fletching and dynamic spine
« Reply #3 on: June 06, 2020, 10:32:52 am »
With 235gr up front you may not even notice any difference with different fletch lengths.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline DC

  • Member
  • Posts: 10,396
Re: Fletching and dynamic spine
« Reply #4 on: June 06, 2020, 11:14:00 am »
Can someone explain why fletching length would affect spine? As near as I can figure spine, static and dynamic, is all about bending the arrow around the bow. This would be mass and acceleration. Fletching change adds very little weight. I can't see how the aerodynamics of the fletching would have anything to do with spine. Puzzled :)

Offline WhistlingBadger

  • Member
  • Posts: 1,728
  • Future Expert
Re: Fletching and dynamic spine
« Reply #5 on: June 06, 2020, 11:39:49 am »
Can someone explain why fletching length would affect spine? As near as I can figure spine, static and dynamic, is all about bending the arrow around the bow. This would be mass and acceleration. Fletching change adds very little weight. I can't see how the aerodynamics of the fletching would have anything to do with spine. Puzzled :)

Same here.  Is anyone aware of any studies on this, or is it one of those bits of knowledge that has passed into the conventional wisdom, but no one really knows why?
Thomas
Lander, Wyoming
"The trail is the thing, not the end of the trail.
Travel too fast, and you miss all you are traveling for."
~Louis L'Amour

Offline BowEd

  • Member
  • Posts: 9,390
  • BowEd
Re: Fletching and dynamic spine
« Reply #6 on: June 07, 2020, 05:46:31 am »
With good bare shaft shooting shafts there is'nt much fletching needed.Personally I hav'nt noticed all that much difference in spine after fletching.As far as drag goes it's the height of the flectching.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline TSA

  • Member
  • Posts: 272
    • www.trueshaftarchery.com
Re: Fletching and dynamic spine
« Reply #7 on: June 11, 2020, 11:15:58 am »
in my experience, it does effect spine, but only minimally, the extra mass adds weight to the rear and this stiffens the spine a wee bit.
i have changed back and forth between different lengths, and i am AR about Tune, i havent seen a difference between fletch lengths.
 more of a difference going from 2 to 3 to 4 fletch, but thats due to the extra mass.
just my .02c

i used to bare shaft, and when i did i always tuned a tad weak, if anything.
But, now i only broadhead group tune. i find it easier, more consistent and easier on shafts