Yanghai (Scythian) bow weight tested

Adam Karpowicz · Post by **Adam Karpowicz** » Tue Jan 19, 2010 7:13 pm

The bow is still in the rough, but the draw weight could be tested. Once it is finished, I will post pictures.

The bow has been kept strung for quite a long time during adjustments with heat, so the string follow is substantial (beyond what can be seen in the old bows on Stephen's pictures). Let's say it is a tired, well used bow. The brace is about 8 inches and most of the bending takes place in the middle of the bow - in the deflexed arms and in the grip. The dimensions are as close as practical to Stephen's notes - the thickness in the middle from deflex to deflex is 23mm, the min. width at the deflexed sections is 17mm, all without the sinew bindings. I expect the sinew binding will add 2 mm for the total of 25mm thick x 19mm wide there. The grip is 23mm thick as well, but widens to 33mm.

The force-draw curve is almost straight all through, with the onset of stacking at about 24in. From 24 to 28in the bow gains 6.5 to 7lb per inch. The draw weight at 28in is 117lb. 28in seems to be the shortest arrow, at 30in the draw weight would be 130-132lb (I did not have the nerve to draw to 30in). The stored energy is about 85ftlb or 115J @ 28in. I think it should be understood that the dimensions can vary for these bows - it can be estimated at about 10-15lb for 1mm of thickness, plus or minus. I am still not quite certain about the thickness of the reflexed parts/tips (I followed the proportions on the pictures) and may decide to make them a little thinner, but the weight should not drop by much.

At this point I am very glad the bow is functional and its draw weight is roughly known. The humidity in my shop was in the mid to low range, about 35-40%RH, so one can expect a drop in weight in humid conditions, probably by some 10lb. Still the bow is quite strong. I can not test the arrow speeds, since my machine is in pieces at the moment and will not be ready until spring.

Adam

JJ · Post by JJ » Tue Jan 19, 2010 7:55 pm

Adam, congratulations! That sounds like big success.

Although the arrows have been long, I cannot imagine the Scyths drawing such a heavy stacking bow to or behind the ears on horseback.

It seems logic that the development of the Hun bow occured mainly because of reducing stack?

Would like to see pictures of that bow....

Best regards, JJ

Adam Karpowicz · Post by **Adam Karpowicz** » Tue Jan 19, 2010 9:30 pm

Thanks. I said stacking, because there is a slight upturn in the curve, but it is not anything dramatic, and may not even be felt by the archer. Something similar to drawing a Korean bow to 30+ inches or another shorter composite.

Adam

jack farrell · Post by **jack farrell** » Wed Jan 20, 2010 3:45 am

Adam, Yes, congratulations. My bow is still way out there. I have never worked on such small sticks for so long, ever.

What kind of wood did you end up using? What kind of horn? -j-

Alan Flashing · Post by **Alan Flashing** » Wed Jan 20, 2010 3:59 am

Adam, look forward to seeing it when you are finished.
Alan

Adam Karpowicz · Post by **Adam Karpowicz** » Wed Jan 20, 2010 10:35 am

Thanks Jack. The horn is water buff with one splice close to tips (for the vert. horn). The core is a combination of birch and maple (birch for the recurves, maple for the deflexed limbs and birch root for the grip). As I explained in another post, even if ibex horn was drastically different in mechanical properties, the draw weight would be affected by only a small percentage.

By the way, the bow has not been seasoned, actually I braced it about a week after the last layer of sinew. This partly explains the string follow (which I wanted for safety). It means the bow's weight is not exaggerated. My apologies for coming up again with these monster bows, but once the original dimensins are faithfully followed, there is no turning back. I would estimate the bows of this style could vary between 80 and 140lb weight @ 28in, since not all were so thick I am sure. It is possible the bows were underdrawn in use depending on the circumstances and the need.

Adam

Kviljo · Post by **Kviljo** » Wed Jan 20, 2010 11:40 am

Awesome, again, Adam! I'm not surpriced by the draw weight at all. Anyone using a bow for more than recreational use and hunting would see the advantage of piercing clothes/etc properly. Looking very much forward to the pictures! Wohoo

Orda Khan · Post by **Orda Khan** » Wed Jan 20, 2010 4:57 pm

Judging by the size of Scythian arrow heads I am more sceptical about the need for armour piercing qualities. I'm sure I've read accounts of Scythians drawing to the chest, which would reduce the weight considerably. It will be interesting to find out how this bow performs.

Patrick Menzies · Post by **Patrick Menzies** » Thu Jan 21, 2010 4:01 am

It was likely range that they were looking for rather than armor piercing ability. There is that record of a 500m shot by a Scythian archer and a bow of that design should be able to do it .

jack farrell · Post by **jack farrell** » Thu Jan 21, 2010 5:02 am

I do not think that drastic would be too great an exaggeration describing the difference between Water Buffalo and Ibex horn. This is a cold bend on a scrap of Ibex.

Adam Karpowicz · Post by **Adam Karpowicz** » Thu Jan 21, 2010 1:20 pm

It would not be too hard to do with buff horn if sufficiently fresh or humid. I had a piece of sheep horn which was very elastic for a long time after harvest, but gained stiffness to become like w. buff horn eventually. Horn keratin should be quite reactive chemically and could crosslink in time depending on conditions.

Adam

Bede · Post by **Bede** » Wed Jan 27, 2010 1:52 am

Regarding draw length, the western Scythians used very small bows and 55-60 cm arrows in general. There are longer bows depicted in Greek pottery with people drawing to the ear. It is likely that the bows from Xinjiang were of the long draw type. The gorytoi are made for much longer arrows, the bows are longer and the arrows also seem to be longer.

A friend of mine gave me some bronze replica Scythian arrowheads and they were both aerodynamic and would have been effective against the types of armour available at the time. The short drawn arrows would still have had a range of about 200 metres and the small cross-sectional area would have guaranteed penetration. Larger bows and longer arrows would have been more effective, but until armour improved the small light arrows were deadly.

Asafan · Post by **Asafan** » Wed Jan 27, 2010 2:07 pm

Many thanks for work, Adam! It is very interesting, how work limbs in your replica, it is possible to show a photo at a draw?

Adam Karpowicz · Post by **Adam Karpowicz** » Wed Jan 27, 2010 7:10 pm

How to post a picture larger than 256K?

Adam

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