Why does the stiff "side" of a bolt prefer up??

[Jerod B.]

Just got my shafts from Jerry at South Shore. They have a dot to index the stiff "side" that goes in between the hen vanes, and subsequently up when loading.

On a compound bow, I had a spine tester, and we used it so we could put the stiff "side" down, to contact the rest.

Just wondering why a bolt prefers to be up. Is it that arrow retainer thingee pushing down against it???

[Boo]

In theory, when the arrow is shot with the stiff sided up. The shaft will flex up, leaving the ends in contact with the mainframe. If shot with the stiff side down, the shaft is in contact with the center of the shaft only. Obviously you want the former condition.
With todays BEA, being so stiff and straight, this is pretty much a non issue for hunting purposes. If it were an issue there would be other things at play. However, if one uses crappy shafts, then maybe indexing would be helpful. But they would have to be spine matched and secondary spines would have to considered.

[SEW]

Thanks, Don. Great, reasonable answer. Your thoughts on indexing 18" Zombies : for 380/405 (with 196g total point wt)? Seems to me to possibly not be needed at all.

[Boo]

Thanks, Don. Great, reasonable answer. Your thoughts on indexing 18" Zombies : for 380/405 (with 196g total point wt)? Seems to me to possibly not be needed at all.

Zombies are 25% stiffer than the Executioners. They are 225 and 300 respectively. I don't want to be responsible for feeding some OCD types but here goes.
To get the most out of arrow shafts you would have to sort a whack of shafts for spine, deflection and location of maximum deflection. Then eliminate shafts with multiple deflection (good luck) or have shafts with minimal secondary spines. Then measure the shafts to locate the area of deflection and orient that area up when located on the mainframe so that the end of the shaft have more contact with the arrow channel.
I think that last part of orienting the shaft is the all important thing to do. There are a few reasons for that. One is the obvious of having a more stable launch (if the arrow sits with most of the contact in the middle of the shaft, the arrow can wobble. Second, IF the shaft flexes, it will cause the bend in the shaft to get worse only.

[diesel]

Ok there is a pic that Jerry at SSA has posted. Might help explain things.
First of all when the arrow is shot it changes and the stiff side is not just a side it is a plane that runs all the way through the shaft . The arrow when shot is going to bent at the neutral plane . If your shooting a recuve or long bow putting the stiff side parallel to the riser is the way to go because the bend of the shaft can help the arrow get around the riser.
With a crossbow when the shaft sets on a rail the rail adds support to the shaft and so the arrow should flex left and right to the rail. It really does not matter if the marked side of the shaft is up or down just so all the arrows are fletched the same.

[ehntr]

Thanks, Don. Great, reasonable answer. Your thoughts on indexing 18" Zombies : for 380/405 (with 196g total point wt)? Seems to me to possibly not be needed at all.

Zombies are 25% stiffer than the Executioners. They are 225 and 300 respectively. I don't want to be responsible for feeding some OCD types but here goes. To get the most out of arrow shafts you would have to sort a whack of shafts for spine, deflection and location of maximum deflection. Then eliminate shafts with multiple deflection (good luck) or have shafts with minimal secondary spines. Then measure the shafts to locate the area of deflection and orient that area up when located on the mainframe so that the end of the shaft have more contact with the arrow channel.
I think that last part of orienting the shaft is the all important thing to do. There are a few reasons for that. One is the obvious of having a more stable launch (if the arrow sits with most of the contact in the middle of the shaft, the arrow can wobble. Second, IF the shaft flexes, it will cause the bend in the shaft to get worse only.

Too late...

[Boo]

Too late...

[Kegbelly]

Thanks, Don. Great, reasonable answer. Your thoughts on indexing 18" Zombies : for 380/405 (with 196g total point wt)? Seems to me to possibly not be needed at all.

Zombies are 25% stiffer than the Executioners. They are 225 and 300 respectively. I don't want to be responsible for feeding some OCD types but here goes. To get the most out of arrow shafts you would have to sort a whack of shafts for spine, deflection and location of maximum deflection. Then eliminate shafts with multiple deflection (good luck) or have shafts with minimal secondary spines. Then measure the shafts to locate the area of deflection and orient that area up when located on the mainframe so that the end of the shaft have more contact with the arrow channel.
I think that last part of orienting the shaft is the all important thing to do. There are a few reasons for that. One is the obvious of having a more stable launch (if the arrow sits with most of the contact in the middle of the shaft, the arrow can wobble. Second, IF the shaft flexes, it will cause the bend in the shaft to get worse only.

Too late...

Are you talkin to ME <in my bad Robert De Niro voice>

[nchunterkw]

I prefer to call it CDO because then it's in alphabetical order

[Jerod B.]

Thanks Boo et al.

I had them sorted to I think .005 deflection.

Maybe a little over board for hunting applications, however, just right for a piece of mind.

[Boo]

Maybe a little over board for hunting applications, however, just right for a piece of mind.

LOL! We have another one! LOL! John, Keith, Paul, take him away!

[newbie]

Me on theses zombies i fletch the cock vane (if i use one gone to solid colors) at the zombies eye. I find he can then use the vane as a sight and are much more accurate
I dont bother indexing tge zombies especially below 18"

[xcaliber]

Mike, (Newbie) I too have quit doing that some time ago, and have noticed no change in my accuracy, especially with Zombies.

[Always]

Ok Ok Ok I get static spine and dynamic spine up and down what does " OCD "
I hate acronyms
..........how can a guy learn with you bunch of intellectuals

A

[Jerod B.]

Ok Ok Ok I get static spine and dynamic spine up and down what does " OCD "
I hate acronyms
..........how can a guy learn with you bunch of intellectuals

A

hint- the D stands for Disorder