Heavy spine on non centershot bows?

[flint kemper]

For you guys shooting non centershot bows let's say 1/4" from center with the leather, are you finding you can shoot a 10 to 15 pound spine weight over with the bow weight with a wood arrow shaft and a 160 to 170 grain head? I really thought this bow would prefer right on the bow weight which is 55@ 28" my draw length and being a string follow bow to boot. Thanks Flint

[Billy]

I'm shooting a 49# not center shot(notched) - with 5/16, 40-45s at 28".

I'm using 200 grn heads.

[Billy]

I draw 26"

[The Whittler]

On most bows not cut to center (long bow for example), a lighter spine arrow works well. A 60# bow might shoot 55/60 spine or 2016-2018 or even less spine.

With your bow at 55#@28" it might shoot a 50/55 or 45/50. Have you tried the lighter spined arrows.

[Daddy Bear]

I think a lot of variables factor into this, but about 12 years ago Jerry Brumm advised me to always start about 10 pounds overspine on his small shelf straight handle Critter Gitter bows. He said to use this as a rule of thumb when using the 160 to 180grain broadheads. At that time I was using both 160 Ace Standards and Grizzlies that weighed around 180grains. He introduced me to Jim Curlee who agreed with this recommendation. Jim made me a full set of tapered test shafts in one pound increments. I used those to bare shaft tune several of Brumm's bows and every single one worked out almost exactly 10pounds overspine exactly as Jerry said.
These were all bows in the 60 to 70 pound range which I drew 27 1/2 inches, and all were with his small shelf.

This was an exclusive experiment with me using only that particular bow design. Much has probably changed since that time and experience with others may vary, but that was a rule of thumb clearly spoken of and used by at least two major players going back over a decade ago. It may very well have some merit. Today I no longer look at it as a given. I just adjust and make changes until the broadhead I wish to use is flying the way I desire. Once there, I don't care what spine the shaft ends up being, be it 10 under, dead on, or 10 over. It is what it is and I don't worry about it. I duplicate it for all the shafts, but I don't concern myself if the spine ends up off the chart.

Best,
DB

[hvyhitter]

I would try going both directions as my non center shot longbow tends to like shafts about 10# weaker for great arrow flight. Its also only slightly R/D and slow,only about 160fps, but wow...so quiet.

[Winterhawk1960]

Doesn't it make a difference whether the riser was cut "in front" of center....or "past center" ??? I'm thinking that would make a difference as to whether it would like a weaker, or a stiffer spine.

I'm sorta new to this game, and perhaps I'm not thinking correctly. Please correct me if I'm wrong.

Winterhawk1960

[Doc Nock]

Hawk,

Center cut makes a huge difference.  Morrison 3/16" PAST center on recurves required me to shoot very stiff shafts... wise friend and bowmaker who messes with arrow tuning/flight a LOT pointed out that far past, or even AT center, the arrow's having a difficult time coming off the string and KNOWING which way to paradox..ergo, an occassional "warble" in flight of my shafts.

I also wanted to UP my EFOC so I have to come back to or SHY of center to up my point weight.

DB points out that in HIS situation, with that bow design.  There are a ton of variables...cast, reflex-deflex, bow/draw weight efficiency, etc.

Center cut is but one of the many tuning options availed to the stick bow shooter.

My Morrison is drawing about 50# at my draw and I shoot a 5575 GT with 260 total front weight. To go up in point weight, I've got to come back to or shy of center. Each shooter's milage may vary!  

[Winterhawk1960]

Doc,

That's what I was referring to, although I might not have been clear enough. I was thinking that a bow cut past center would require a stiffer shaft, and one cut in front of center would require a weaker shaft.

The only bow that I currently have is cut to center, but I have one on the way that is cut past center. They most likely won't shoot the same shaft, unless I change tip weight.....is this correct ???

I know that bow design has a lot to do with it too, but am really lost when you get into that discussion.

Winterhawk1960