New bows from Kaya in 2011

This is where we discuss the bows, arrows, quivers and other hardware used in Asian archery.
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Thomas Duvernay
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Re: Korean War Bow Replica

Post by Thomas Duvernay » Sat Feb 05, 2011 3:58 pm

WarBow wrote:
Justin Ma wrote:
WarBow wrote:Just out of curiosity, is there a bowyer in South Korea or elsewhere who can make Korean war bow replicas using a mix of modern and natural material in the 120 lbs draw weight range? At what draw length is the 120 lbs peak draw weight measured at? 31"?
It may not be the size you're looking for, but I imagine its draw weight is greater than 120# @ 31": http://www.koreanarchery.org/punbb/viewtopic.php?id=70
That's so hilarious! :D

It's still for sale, as far as I know...
J-Boon
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Location: Australia, Melbourne

Post by J-Boon » Fri Feb 18, 2011 11:37 am

I?m a recreational archer, I don?t go to or join any clubs and I shoot solo at my place. Nothing complicated. Since relocating/moving to Australia years ago, I?m fortunate to be able to have personal space to do archery by myself. I stand in the driveway and my target is placed ?inside- the garage which I shoot into. What this means for me, is that, my arrow trajectory can?t be too high. (From floor to the top of the garage its about 2.1 meters). The driveway which I shoot from, is shielded on the left by the house and on the right by a 2 meter fence separating my place from the neighbours. Essentially its like an alleyway, shielded from wind.

I shoot usually at 17meters (18.5yards) and the maximum distance space I can afford at my place is 20meters. I use a 60cm FITA target paper and I shoot every evening after work (unless theres heavy rain). My only gripe about my setup is that there is a resident brustail possum somewhere around the neighborhood that insist on pooping at my driveway every night without fail, which means I have to sweep the driveway before shooting unless I want to trod on possum turd.

Anyway, I was reading this thread, about Korean Bows, Horsebows, and how the thread diverge at some point. While I won?t comment about draw weight on horseback, or draw weight in ancient time, I thought of contributing my opinion/review on some of the bows that were mentioned, since, I own 2 of the types commented.

All my bows are considered ?low? poundage. I don?t shoot high poundage bows due to a past injury where the base of my right thumb was sliced to bone, the good thing that came out of it is, my thumb, till this day is numb and I don?t really feel any crimping even if I don?t use my thumb ring (I still do use thumb rings anyway). The bad news is, I am not exactly doing a ?true? thumb draw. I physically can?t bend my right thumb on its own and I use my index or index+ middle finger (depending on the bow I use) to basically lock the thumb. There is absolutely no pressure exerted by my thumb since, I cannot bend it on its own and strength comes solely from the lock of the index finger or index/middle finger. It?s a physical limitation that can?t be helped, I guess.

I have always used ?bare bows? (no arrow shelf) and I?ve have never done archery any other way than shooting it off my thumb (on the right side of the bow) and using the thumb draw. So, I can?t really comment how these bows shoot using the Mediterranean draw or otherwise.

Early this month in Feb I received my Hwarang Bow which I ordered through Thomas Duvernay, increasing my bow collection to 3 here in Australia.

The three bows I own are

1. Asymmetrical ?Hun-styled? Bow (Kassai ?Deer?)
Height when braced: 160cm (63?)
Manufacturer claimed draw weight: 25# at 28? (I draw the bow to 35? so ~43#)
Bow weight: 1kg

2. Japanese Yumi (Higo Sozan Carbon Yumi)
Height when braced: Ni-sun nobi 227cm (89.4 ?)
Manufacturer claimed draw weight: 38.5# at 35.4? (17.5kg at 90cm)
Bow weight: 540grams (Not entirely sure)

*Comment: Ni-sun nobi yumi draw strength are measured at 90cm


3. Korean styled carbon Bow (Hwarang Bow-long version ?Janggung?)
Height when braced: 122cm (48?)
Manufacturer claimed draw weight: 35# at 31? (I draw to 33?)
Bow weight: 360-384grams (extremely light)

* Comment: Around 29? of draw, the pull becomes very hard, feels like stacking, but
since the manufacturer measures draw weight at 31? I guess this is normal, for a
Korean bow.


I own 4 sets of arrows. That I switch around depending on the bow (and my mood)

- 10 German Cedar arrows: 85cm (33.3?) weight: approx 38grams (586.4 grains)
- 20 German Cedar arrows:83cm (32.7?) weight: approx 38gram (586.4 grains)
- 20 Easton Powerflight Carbon arrows: 81.3cm (32?) weight: approx 24g (370 grains)
- 50 Tiger Tonkin Bamboo arrows: 95cm (37.4?) weight: approx 38g-42g (586.4 -648
grains)

Kassai Asymmetrical ?Hun-shaped? Bow (Deer) vs Korean Carbon Jangung (Hwarang Bow long version) my personal opinion.


Drawing/Pulling

The manufacturer draw strength for my Kassai ?Deer? asymmetrical ?Hun styled? Bow is 25?@28?. I draw the Kassai bow to (believe it or not) to 35? even though this particular Kassai bow model states the max draw length is 33?. (That?s the main reason why I got this bow, I look at what draw length the bow can handle, and got a bow with the longest draw length I could find).

The pull from 28? all the way to 35? feels exactly the same. It is smooth and even, that?s the best I can describe it. (i.e you don?t feel any increase in strength to pull back all the way to 35?). It?s a bit creaky but not really noticeably unless you?re being picky (sound-wise) when you draw the bow, I have a gut feeling its due to the way the string loop is made, not so much the bow. Since the bow pull is so even (i.e the pull is not exponentially difficult to pull from 28? to 35?, I give it the benefit of doubt and take the poundage to be linear (no scientific basis for this conclusion) I calculate the poundage at 2.5# per inch so at 35?, I am guessing the poundage is roughly 43#. The Kassai Deer, does not feel like 43# when you draw it to 35? because my Yumi which is 38.5# at 35.4? feel way more harder to pull in comparison. You could probably draw it all the way pass 35? but my arms aren?t long enough to find that out.

As for the Hwarang Bow. A number of Atarn members own the Hwarang bows, I wonder if they have the same experience as I have with the Hwarang Bow. The Hwarang bow pull is very smooth. It?s a different quite of smooth feel compared to Kassai Bow. I liken the feeling of the Hwarang Bow to that of pulling a rubber band/elastic tubing, while the smooth Kassai deer feel like pulling on? well.. bendable wood (kind of feel somewhat like a pulling back on a yumi with sound). It is a very enjoyable feeling. The pull is way quieter compared to Kassai Deer. However, at the start of 29?the Hwarang bow, feels like massive stacking and at 30? it feels like hitting a brick wall and at 30? it feels like you can?t pull anymore, but it can?t be true, that?s what I thought because the manufacture measures the draw weight at 31?.

Maybe the initial pull back is almost nothing , that it "tricks" the arm to think it has hit a brick wall at the last few inches, or maybe it is really stacking. Since, I?ve never used a Korean traditional bow, I?m keeping an open mind about it.That being said, the Hwarang bow CAN be pulled all the way to 33?. (I use my 33.3? german cedar arrow to test this). After shooting daily, pulling the Hwarang Bow to 33? seem to be really easy now. It doesn?t feel like ?hitting? the brick wall anymore, but it still feels hard to pull pass 29?. I don?t know if it?s a matter of me getting use to it or the bow has ?soften? up. One thing for sure about the Hwarang bow is that from 30?inches onwards (or maybe 29?), the strength required to pull back is not linear but exponentially, compared to the Kassai ?Deer? Hun bow, where the pull from 28? to 35? feels exactly the same. Bear in mind this is with the long version of the Hwarang Bow, the jangung. I?m guessing the standard Hwarang Bow will have a much difficult pull at shorter draw lengths.


Arrow speed.

I usually use Cedar arrows to shoot with the Hwarang, and Bamboo arrows for my Yumi and Kassai Hun. But for comparison, I will cite my experience using Bamboo arrows to cross-compare between the 3 bows I use:. Kassai Asymmetrical Hun, Hwarang, Higo Sozan Yumi.

The Hwarang Bow launches arrows very fast. The arrow speed of the Higo Sozan Yumi and the Kassai Hun bow pales in comparison. (Hwarang Bow > Higo Sozan Yumi > Kassai Deer Hun) The speed is very visually noticeable. Then again the comparison is not exactly without bias.

The Hwarang uses Fastflight strings, the Yumi uses Aramid/Kelvar and Kassai Deer uses Dacron. Also, I?m pretty sure the poundage with the draw length I?m doing is not equal among the three. Since, my Yumi draw weight is know exactly (38.5# at 35.4? (90cm) ), I use this as a empirical way to guess the draw weight of the 35# @ 31? Hwarang Bow at a 33? draw. At 33? the Hwarang does not feels as heavy to draw, compared to the Yumi. So I?m guessing at 33? It is more than 35# but below 38.5#.

Whilst, I calculate the Kassai ?Deer? Hun styled bow to be 43# at 35? draw (Manufacturer states 25#@28?). It feels way easier to pull. To me it almost feels less than 25# all the way to 35?. The pull weight is so even from 28? to 35?. In terms of evenness of pull between the 3 bows, (to me at least). Its Kassai ?Deer? Asymmetrical Bow > Higo Sozan Yumi> Hwarang.


Arrow trajectory.

This is something, I?ve been wondering for a while due to my observations. My Yumi and Kassai bow are both asymmetrical. The Hwarang is not. The Kassai ?Deer? Asymmetrical Bow arrow trajectory is definitely flatter than the Hwarang even though it launches arrow ?way- slower. The Yumi (which is also asymmetrical) trajectory is also flatter compared to the Hwarang, but not as flat as the Kassai Bow. This was observed using the bamboo arrows. I definitely have to aim low with the Hwarang Bow and not the Kassai bow or my Higo Sozan Yumi. For the Yumi, its hard to compare because the shooting technique is different. I use the same style on my Kassai Bow with the Hwarang. (i.e Grip, Stance, Anchoring, release). The Yumi definitely hits ?low? given the same height of target. Maybe because the center of target to the ground is normally 27cm in Japanese archery and the Yumi is designed that way (No idea). I find I have to adjust aiming (Nerai) of the Yumi upwards, since my target is at chest height and not the traditional height level. Also the arrow I use on my Yumi are way heavier than those used in Kyudo. (much more heavier than kinteki arrows). Also, since Kassai Hun style bow and Hwarang Bow are fundamentally different in shape and I?m using the same style on them, maybe its not even accurate for me to say that Hwarang Bow trajectory is less flat than Kassai Bow. It could be a case of different technique for different bows. So, caveat there on that observation.


Handshock/Vibration

You don?t feel any handshock or vibration at all with the Hwarang Bow or Kassai ?Deer? Asymmetrical Bow. With the Higo Sozan Yumi, you do feel it, but it depends on the way the Japanese bow is used. The handshock on the Higo Sozan Yumi is minimal, (at least to me), but in no way can it compare to Hwarang or Kassai Deer. I don?t use the standard brace height of 15cm for my yumi. (Mines a bit higher), so that helps with the vibration a little, I hazard a guess. Then again the Higo Sozan Yumi back curve is suppose to resemble closest to a bamboo yumi among the synthetic yumi and hence (manufacturers claim) the least handshock among the synthetic yumis.


Penetration of target

Kassai ?Deer? Asymmetrical Hun styled bow, even when pulled to 35? (and theoretically have the highest poundage among my three bows, but I must add, the theoretically calculation doesn?t seem to match the feel) penetrate much less deeper than the Hwarang Bow or the Yumi. (This is with the heavy Bamboo arrows). The Yumi penetration is deepest among the three bows I have, although the Hwarang bow penetration is somewhat similar. Both arrows launched from the Yumi and the Hwarang have in some cases flew right through my double straw target backed by heaps of cardboard. and embedded right into a 2.5cm thick chip board I use as a backing wall about 1 meter behind the double straw+cardboard target. Then again with shooting arrows usingthe Yumi, if you twist the string in a particular way to get an ?S? shape you can kind of get a bit more penetration power.

In closing, the feel of the Hwarang Bow is definitely different from Kassai Bow. The Hwarang Bow is extremely light to the point it ?feels? flimsy. But it is extremely fast and powerful (More penetration power) compared to Kassai asymmetrical deer. It is very small and compact as well. However, if you like the long draws (like me), you might not get use to the Hwarang Bow (You might even feel a tad be disappointed) because the Hwarang bow draw length to me is short (and this is with the long version of the Hwarang), and the pull to reach the draw length that I?m minimally comfortable with is not ?even?. (It requires exponential amount of strength to pull from 29? onwards, but you will get used to it eventually). If you like very even draw (from 28? to 35? it feels same to pull), the Kassai ?Deer? asymmetrical bow is where its at.

Oh yes? one thing, I?m sure every Hwarang Bow owner will know, The ?death by a thousand shiatsu massages? on your bow hand. (I?m sure every Hwarang Bow owner will know what I mean, lol). I wonder if the Kaya traditional bow uses the same grip as the Hwarang, if so, beware!

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Storm
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Location: Romania

Post by Storm » Fri Feb 18, 2011 12:23 pm

WOW! Really nice review, thank you J-Boon!
"death by a thousand shiatsu massages"

This is so hilarious! :lol:
I did not liked that grip material at all and I switched to rubber grips used for tennis racquets. Works great for me but it depends how steady of a grip you need.

The Hwarang is also asymetrical, not in limb size, but in shape and strength; the top limb is curved more and a bit lighter. Kaya and Wind have the same setup.

Regarding the draw feeling, you are right, it goes a bit exponentially after some point, but for me it's ok. After around 29-30" my back starts pulling almost all the weight, so I don't really mind. It has a similar graph to Kaya and Wind:
http://www.aixbow.de/shop/images/diagra ... al_bow.pdf
http://www.aixbow.de/shop/images/diagra ... rbogen.pdf
I have abused my bow at 33-34-35" for about one and a half years and there's absolutely no issue with it (49# @29"). I finally settled at 33" for target shooting, but when shooting up is easy to draw longer.

I don't understand why you say the Hwarang trajectory is not as flat. You say that "I definitely have to aim low with the Hwarang Bow and not the Kassai bow or my Higo Sozan Yumi". Aiming low and hitting the same spot indicates that the arrow looses less height with the Hwarang, so the trajectory is flatter. Or am I reading this wrong?

Nice bow collection!
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Thomas Duvernay
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Post by Thomas Duvernay » Mon Mar 28, 2011 2:00 am

I just received the Khan test model from Kaya. I will be rather busy in the next few days, so I'm not sure when I'll have a chance to test it out, but I will do so ASAP. However, out of the box, it's beautiful and feels great to draw. 45# @28"

More later!
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Thomas Duvernay
Posts: 440
Joined: Sat Mar 12, 2005 11:37 pm
Location: hometown: Michigan, USA/current location: South Korea
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Post by Thomas Duvernay » Sat Apr 09, 2011 5:55 am

Well, I got to shoot the Khan for the first time today; however, I didn't have a lot of time to do so. I was having my Korean history/culture students over to the club today to introduce them to Korean trad archery, so by the time I got set up, they were already arriving. On top of that, regular club members were coming to practice for the upcoming provincial competition, so we had to be done by 2 p.m.

Still, I got to shoot a few arrows. My general opinion of the bow is good. It was a 45# @28" bow and I was shooting 500gr wood arrows with it. Speed-wise, they were mostly in the 160s, but I had a couple in the 170s. In comparison, my 50# @31" Hwarang shot 405gr arrows about 210fps. In short, the Khan will be a nice bow for those wishing to shoot fingers @28". I'll try to find a time when nobody else is at the club and I'll do further testing, but I think, overall, it's a really nice bow.
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