# Arrow Spine: Cons of Too stiff?



## tailhappy (Feb 25, 2019)

After searching & reading tons of post about arrow spine, I'm still unclear about overspined (too stiff) arrows. Can anyone explain the physics behind the cons of overspined arrows. While many posts note the preference for overspends over underspined (flimsy) arrows, the cons of overspend arrows remain vague. 

I target shoot a recurve bow and use 33" long arrows (31.5" draw).


----------



## AUSSIEDUDE (Apr 17, 2009)

Spine is confusing for a new guy to archery, there is so much misinformation out there.
Don't confuse compounds and recurves/longbows when it comes to spine. The physics involved with compounds in regard to spine is just having a strong enough arrow to withstand the considerable power stroke of the bow and this varies with the tune of the bow. A well tuned bow where the power is transmitted through the centerline of the arrow can safely shoot a much weaker arrow than a poorly tuned bow where the arrow leaves the bow with less stability.
With a recurve or longbow the physics are much different and spine is critical for good arrow flight. Because the cutout on most recurves does not go deep enough for the arrow to be shot through the centerline of the bow the string does not travel in a perfectly straight line, it gets pulled very slightly to the left (right handed shooters) trying to follow the arrow, this puts a left to right flex in the arrow. It is the spine of the arrow that regulates the amount of flex that the arrow absorbs and it is the control of this flex that allows us to get the flights of the arrow past the riser without contact. Too stiff a shaft and the arrow will not flex enough for the flights to clear the riser, too weak a shaft and a lot of the bows energy will be lost in the arrow, though the bow should still shoot accurately because there is no fight contact.


----------



## Rat (Jun 19, 2004)

In compound archery (with a release aid) too stiff isn't a thing except for fixed blade broadhead flight (that's a generalization, but it holds true much of the time).

In recurve archery spine is everything.


----------



## eoj823 (Jul 25, 2016)

Agree with a compound ive been able to get a stiffer arrow to fly well but under spine arrows can be a pain.


----------



## Propknut (Apr 8, 2018)

On a recurve bow, arrows that are too stiff will wag their tails as they go down range. They will not flex enough on release and that starts the tail wagging oscillations. Adding more weight to the front will weaken the arrow, effectively increasing the spine number.


----------



## tailhappy (Feb 25, 2019)

Thanks for the replies everyone. I've since found a few posts addressing my original question (e.g. here) so I'll let this thread die even though I think the issue could use a summary/consolidation. Seem like there needs to be a Forum discussion category called "Theory" since I don't want my geek ramblings to disturb pragmatists who just want to build good arrows. Cheers!


----------



## hishtasoul9 (Apr 17, 2020)

They will no longer flex enough on release and that starts the tail wagging oscillations. for buying the electric smoker Adding greater weight to the the front will weaken the arrow, efficaciously increasing the spine range.


----------



## saub74 (Jan 27, 2016)

Following


----------



## merlinron (Mar 23, 2020)

with today's compound that are truly "center shot", stiff spine is the norm. the arrow doesn't need to bend around a riser anymore.


----------



## diewindowsdie (Dec 2, 2018)

From experience, I can tell you that weak setup (arrows are weaker then your bow) is way more forgiving for your technique imperfections. With a stiff arrow, slight plucking can cause rear of the arrow to hit your rest or plunger, ripping vanes, damaging a nock or an arrow wrap. So, as long as I have a choice, I'd go for slightly weak setup as you're more likely to "underpull" the bow rather then "overpull".


----------



## mchasal (May 11, 2020)

I've just been looking at arrows for my incoming Bear Approach HC (and I hope this isn't a hijack). The bow is rated 55-70# and looking at the spine charts, there's a bit of a range that would cover that. For example, Black Eagle lists a range starting at 350 for the lower weight and up to 250 for the max. I'm inclined to get the 250s as they should be fine for all the weights the bow is capable of, though obviously be overly stiff for the lower weights, but from what I'm reading here, that's ok? I might have a better idea of what final weight I land on later, but initially just want to make sure everything is safe. 

Thanks for checking my sanity.


----------

