why tonkin bamboo shafts and arrows might fail.

[Todd Mathis]

So I spent a good deal of time reviewing a failure of these shafts and one arrow by a recent customer who was kind enough to send photos and all the info.  It is important for me to set fair expectations and help you be successful with what I offer...otherwise...well you get the picture.  There were several unique factors with what had happened with this customer and the problems encountered.  After reading up and doing some research on why his arrow shafts failed, I believe I now understand.  Because I want you to know what to expect, I put this info up on Bamboo Arrow University.  I want to thank everyone who helps me do a better job.  Thanks to Jim Richards for stepping up.  I owe you some shafts...and a beer.   The explanation is posted at https://khansarrows.com/more-info/product-testing/ 

[artcher1]

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

[aaron]

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.

[razorsharptokill]

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.

[willie]

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, bare shaft tuning before fletching makes 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.

[artcher1]

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

[razorsharptokill]

1" of weight??

[artcher1]

1" of weight forward from the center of the shaft Jim. Find the center of your shaft and mark it, then balance the shaft on a pencil or something and mark that. Distant between the two marks is the amount of weight forward that you must account for...….Art

[Mesophilic]

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.

[DC]

Have you tried throwing in a wet towel? I'm still thinkin' that moist storage is your answer.

[Mesophilic]

Have you tried throwing in a wet towel? I'm still thinkin' that moist storage is your answer.

No, decided it's not worth it to have to baby gear meant for hunting.  It's also an issue of being able to trust my gear...say I go to another 3D shoot at the pueblo, and it's hot and sunny with no shade.  Can I trust that my humidor pampered arrows won't dry out too quickly and warp or crack?

[Deerhunter21]

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

[DC]

It slows it down but it doesn't stop it.

[Mesophilic]

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.

[Deerhunter21]

Hmm. Let me think. I have some ideas i believe.