why tonkin bamboo shafts and arrows might fail.

[Todd Mathis]

It sounds to me like the bare shaft arrows did not stabilize in flight before hitting the target. In your post on your website, you say that they had stabilized- why do you say that? Some of the language used on your site is not really clear to me. "When I say my ARROWS are tougher than carbon, there are a few things I never considered.  I DO NOT MEAN that my SHAFTS are tougher than carbon.  Shafts can break quite easily.". I don't understand what youre trying to say here.

the picture shows the arrow perpendicular to the target, but it could have been waggling back and forth and just happened to stick into the target perpendicular.

I think you're setting some pretty high expectations in your marketing. Bamboo arrows break too.

Fair enough.  my arrows are that tough...but not until they are an arrow.  What I am learning is that until the feathers are on and the arrow stabilizes in flight, it is just a stick wobbling through the air.  Because it is a hollow grass tube, the shear (sideways) stress of it hitting a very hard backstop and not being lined up with the weight behind the head just might not be successful at all.  Shafts are not the toughest, just the arrows.  Thanks for pointing this out.  I'll go look at my website again. 

[Todd Mathis]

It sounds to me like the bare shaft arrows did not stabilize in flight before hitting the target. In your post on your website, you say that they had stabilized- why do you say that? Some of the language used on your site is not really clear to me. "When I say my ARROWS are tougher than carbon, there are a few things I never considered.  I DO NOT MEAN that my SHAFTS are tougher than carbon.  Shafts can break quite easily.". I don't understand what youre trying to say here.

the picture shows the arrow perpendicular to the target, but it could have been waggling back and forth and just happened to stick into the target perpendicular.

I think you're setting some pretty high expectations in your marketing. Bamboo arrows break too.

You could be right about that.  But here is the coincidental info.  I have never ever had 3 shafts break in an order on the first day of shooting.  I have seen the shafts break sideways through the shaft instead of shattering along the grain when the shear (sideways) stress of pulling one out of a wooden target is too much.   ALSO, this is the first time I have sold any to a customer who does bare shaft tuning that I am aware of.  So...I put this all up to set realistic expectations..  All I am trying to say here is that I think I found a quick way to break them so that you might want to tune your arrows a different way than bare shaft tuning.  Last thing I want is a customer who feels I sold them an inferior product.  Thanks for the feedback!

[Todd Mathis]

That was my arrow that broke and yes it was flying nock high. The back side of that piece of foam is VERY ridged. I have stopped using it to shoot at. The fact that the shafts were nock high and  the angle of the foam is what broke the shaft. ANY natural material shaft  probably would have broken in these circumstances.

Once I got things set up properly I have great flight. These shafts are different than wood. Plainly just a different animal. Foremost, they are hollow therefore lighter. The shafts I have are 50-55 spine cut to 29.5". With a 37 grain box nail inserted(on three shafts) in the tip and a 145 grain tip they weigh just shy of 500 grains.

I say this because to get 10 grains per pound of draw weight like a lot of people like for hunting, you may have to go stiffer if you are going to add weight up front.

 I am new to a bamboo arrow so I am going to continue to run them through their paces and see they fit my needs. Over all I really like them so far.

Thanks for the insight.  I am NOT a hunter due to health issues.  I am a "range plinker".  That heavier weight is excellent info so that people will know if these are the best shafts for them.  Alas... nothing is perfect.   

[Todd Mathis]

interesting read....
(from the university)

The last point is that I have never had a customer use bare shaft tuning on their bamboo order before.  My suspicion is that bare shaft tuning may be incompatible with the bamboo I sell.

A recommendation you might offer for bareshaft tuning is to start out very close to the target so that the arrows is not too  "sideways" when it hits.   moving back as the shaft and point weight  is tuned  to the bow better.

Its easy to stabilize with lots of spiral and more feather than needed. For those that are concerned with minimizing speed loss for longer shots, having a tuned shaft makes more sense as less fletching is needed.

I suspect that many of your customers get by shooting stiffer arrows than needed  because their bows are more centershot. The fiberglass bow world seems to prefer tuning the bow, whereas  wider handled/natural materiel bows need to have arrows that  are finessed a bit more.

"Its easy to stabilize with lots of spiral and more feather than needed. For those that are concerned with minimizing speed loss for longer shots, having a tuned shaft makes more sense as less fletching is needed. "
I completely agree...once the shaft has become an arrow, these arrows are tougher'n hell, but apparently not until they are balanced and completed arrows so they stabilize in flight is all I'm saying. 

[Todd Mathis]

Hi Jim, once you know your spine requirement for your bow it's a simple matter of a little math to know what spine to order. Add 5# of spine for every inch over 28". Next, your supplier will have to add 5# for every 1/2" of weight forward of the shaft. For example: you want to build a 40# arrow that's 29.5" long BOP using a 125gr point. You would add 7-8# for that 1 1/2" over the normal starting point of 28", and then say you have 1" of weight forward on the shaft, you would add 5# per 1/2". That's 7-8# plus 10# added to the shaft. So if I've done my math correctly, you would need a 57-58# spined shaft using a 125gr point to achieve a 40# dynamic spined arrow...….Art

This is very interesting to read!  I assume you hunt?  I would love to chat on the phone to learn more about this math.  It would be helpful for me to understand better how to build these arrows for a situation I don't fully appreciate.  As previously stated, I am not a hunter because going to the woods would be hazardous to me, so I am a range "plinker".  If you ever feel inclined I would like to learn more.  Feel free to call if you're feeling generous!  Cool insight.

[Todd Mathis]

Since this topic is about bamboo breaking, I figure I'll mention my issues with it.

I've tried a few different bamboo shafts, I won't go in to supplier details for obvious reasons.  They do great when we actually have humidity.  I live at 7500 feet in New Mexico and our normal humidity levels are extremely low most of the year, below 10% a lot....combine the elevation and lower vapor pressure, its sort of like a wood freeze deyer up here.

We had an unusually wet summer in 2019.  I shot the heck out of my bamboo arrows.  Shot a bunch of 3D, had many misses and didn't break a single shaft.   Bounced them off of trees, hit rocks, etc.  Then the weather dried out.  And now any deflection off of a tree or stump shatters the bamboo.  Rocks are instant death.   My douglas fir shafts suffer from the same fate.

My moisture meter regularly reads wood here at sub 5%, not just on the outside mind you,  but even after freshly cutting in to it, so I have to assume my arrows would have a similar moisture content.

I'm in the process of throwing in the towel and eyeballing carbon at this point.

I throw this out there just as a suggestion for Todd to take environmental  factors in to consideration as you analyze breakage.

YEP!  I'm still trying to figure this out because I live in a fairly humid area.  San Antonio, TX. is hotter'n hell and very humid much of the time.  I have often wondered about that.  I have a customer who lives in northen New Mexico.  He says they never break for him.  He loves them because they are tough.  curious....  Do you hunt with your arrows too?  I'd love to hear more about your bamboo experiences.  interesting point....

[Todd Mathis]

Stupid question but are they sealed? If you humidify them and then seal them with tru oil it should stop the moistuer from comimg out

wow!  if that works it is simple to do!  hmmmmm....

[Todd Mathis]

Stupid question but are they sealed? If you humidify them and then seal them with tru oil it should stop the moistuer from comimg out

Sealed with Tru Oil and periodically rubbed down with a paste wax.  As DC stated, it can slow down the moisture loss but I don't think any finish could completely stop it.

I hope this isn't galactically stupid, but I have arrows that are 10 years old and don't show any evidence of being brittle or dried out, but I used them for archery golf and horse archery into reasonable targets.  I can see that a can of worms has been opened here.  If anyone has experience with humidity effecting bamboo, I'd love to hear more...

[Deerhunter21]

what area do you live in?

[Todd Mathis]

I appreciate all the feedback.  My experiences with these arrows do not include hunting, but they do take a tremendous amount of abuse from my other experiences.  Now I spend my time trying to learn to make them group into a teacup at 20 yards so that they are tough and predictable, but on a range.  Never had them break at 3D or normal horse archery either, but my usage of them is limited because I don't hunt.  Thanks guys.  If anyone wants to give me some more feedback, I DO LOVE a good conversation and would like to hear more about what your thoughts are.  Best of shooting to all.

[Todd Mathis]

Well, I never saw and arrow shaft I couldn't break. They all fail under the right circumstance. That's a fair expectation. I once mounted an authenic Indian arrow head on a Tonkin shaft and shot it into an Oak tree until the shaft shattered. Never did damage the arrow head. Go figure...……..Art

hahahahaha!  Alas...

[Todd Mathis]

It sounds to me like the bare shaft arrows did not stabilize in flight before hitting the target. In your post on your website, you say that they had stabilized- why do you say that? Some of the language used on your site is not really clear to me. "When I say my ARROWS are tougher than carbon, there are a few things I never considered.  I DO NOT MEAN that my SHAFTS are tougher than carbon.  Shafts can break quite easily.". I don't understand what youre trying to say here.

the picture shows the arrow perpendicular to the target, but it could have been waggling back and forth and just happened to stick into the target perpendicular.

I think you're setting some pretty high expectations in your marketing. Bamboo arrows break too.

Fair enough.  my arrows are that tough...but not until they are an arrow.  What I am learning is that until the feathers are on and the arrow stabilizes in flight, it is just a stick wobbling through the air.  Because it is a hollow grass tube, the shear (sideways) stress of it hitting a very hard backstop and not being lined up with the weight behind the head just might not be successful at all.  Shafts are not the toughest, just the arrows.  Thanks for pointing this out.  I'll go look at my website again.

Shaft vs. arrow.  One is balanced and fletched.  The other isn't...I should make it clearer that I mean that.  Thanks.

[Deerhunter21]

Hey todd, I would love to find a time to ask some questions and just talk if your up for it!

[willie]

This is very interesting to read!  I assume you hunt?  I would love to chat on the phone to learn more about this math.

Todd
the previous sponsor posted some good links that help understand lots of the math.
the search function in the forum is not the best, but if you click on his username and look at his posts, or better still search the attachments to his posts......

BTW, Welcome and thanks for becoming the new sponsor

[Deerhunter21]

Who was the last sponsor