Tapered Shaft Question

[William Warren]

#6490

Does tapering a shaft change the spine of the shaft and could you use tapering to intentionally change the spine of a shaft?

Inquiring minds want to know 😀

[Doc Nock]

#51863

Duncan,

I know what I was told over the years, but so much of the “old school” data has been challenged and refuted…and since I no longer shoot or mess with wood, even though I barrel tapered and bought RRA nock tapered cedar decades ago, I’ll wait to see what the current sage advice from our woodie vets say!

[jpc]

#52168

Duncan wrote: Does tapering a shaft change the spine of the shaft and could you use tapering to intentionally change the spine of a shaft?

Inquiring minds want to know 😀

Sometime spine changes between two same wooden arrows 🙄

[Doc Nock]

#52341

JPC,

had to read that a couple times….I thought you said that spine changes time to time in the same wood arrow…

Now THAT would be a revoltin development!8)

[Stephen Graf]

#52343

I would say the answer is: yes, but…

If you add or remove material from the arrow it will change the spine. The problem is in how you measure that change. The technique we use to measure spine is to support the arrow by two points separated by a known distance. Then hang a weight between the two points and see how much the arrow bends.

By removing part of the arrow as we taper it, we have changed how the arrow will sit on the 2 points. It will naturally be lower now. In addition, where we choose to measure the arrow will affect the reading too. Measure closer to the back and the arrow will be weak. Measure closer to the front and the arrow will be stronger.

So the standard is to measure the spine before tapering. Taper the arrow, then shoot and see how it goes. When you buy tapered arrows, they are grouped and sold by the spine measured before tapering.

[Jason Wesbrock]

#52468

I suppose the short and simple answer is yes. If you remove material from the shaft (sans point and nock tapers) you will weaken the static spine. As to how much, it depends on how long you make the taper and how much material you remove. It probably depends on what kind of wood you’re working with.

Back when I shot wood arrows I used to taper mine from 11/32” to 5/16” in the rear 10”. I have no idea how much that powered the static spine because that was before I had a spine tester. I would be curious to hear from someone who’s checked them before and after. If I had to take a wild guess, I’d say it probably didn’t change them by more than a couple pounds at most.

[Abel]

#52507

I asked this to the couple of gentlemen who have turned shafts for me, they all have said that tapering will usually drop spine by 2-3lbs on average with your standard 10″ taper. Now, how about dynamic spine? With the taper, in theory the arrow should recover from paradox quicker correct? I know that the 70-75 spine cedar I has shoot better and recover quicker than my 80-85 spine parallel cedars shooting the same 300gr heads.

[Ralph]

#52553

I don’t remember the spine of some cedar arrows I had years ago but I do know they were 23/64 shafts cause at that time that’s all I used, actually they were the most common way back then.

These shafts were maybe 7-8#’s too stiff so I tapered them down to 11/32. I’m thinking that dropped the spine maybe a pound or so. So then I decided to barrel taper them and see what happened. I tapered the fronts down to 11/32 also. Probably 9″ both ends as that’s what I always do.

As I recall after all that work I maybe got the spine down 3 #’s.

But like Steve pointed out, everything sat differently on my spine tester so who knows about the accuracy of my experience.

Seems though if you zero the tester it ought be OK. ???

Good thing from that though was I built my tapering sanding tool and still use it, not only for tapering but for sanding arrows before putting a finish on them.

[Greg Ragan]

#52788

Abel wrote: I asked this to the couple of gentlemen who have turned shafts for me, they all have said that tapering will usually drop spine by 2-3lbs on average with your standard 10″ taper.

This has been my experience…A longer taper may drop more pounds from there.

Typically a 10 inch taper for me still keeps me in the ballpark.

[William Warren]

#54188

Thanks for all the replies. I think I’ll try one and see what happens. I wanted to try to make some 50-55 11/32s work in my 50 bows without going over 160gr on the tip. Cutting them longer is also a thought. My draw is 26″. and I used to shoot 55 and 60+ but not in few years.

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