Gansu, Niya
When working on the f-d curve I remember the Gansu bow. It has two bending parts.
My thinking is, if the limb bends in the beginning and store heavy weight till the ear start to come around and the draw length is normally reached, if we draw more the bow explode. But if the other bending part in the siyahs starts to bend and give longer draw length, would we not have a longer power stroke and store more energy?
My thinking is, if the limb bends in the beginning and store heavy weight till the ear start to come around and the draw length is normally reached, if we draw more the bow explode. But if the other bending part in the siyahs starts to bend and give longer draw length, would we not have a longer power stroke and store more energy?
After having seen and handled many of these Niya-type bows, I can now say that there was only one working part of the limb.
Grozer has made an exact replica. Its effective draw-length would not be more than 30". The arrows with it bear this out.
S
Grozer has made an exact replica. Its effective draw-length would not be more than 30". The arrows with it bear this out.
S
Ok, but would it have work if it had two working parts?
The picture from http://www.atarn.org/magyar/niya.htm showed that the Niya bow had two working parts though.Stephen Selby wrote:
After having seen and handled many of these Niya-type bows, I can now say that there was only one working part of the limb.
Grozer has made an exact replica. Its effective draw-length would not be more than 30". The arrows with it bear this out.
S
Dwanyin: yes it did say that. And I drew that picture, and it was wrong. :oops:
Back to the question: what if I had been right?
My view: it would not have been a bow with two working parts to each limb; but a bow with two working limbs with a useless bit of sold wood adding unecessary weight in between them.
What is of much greater interestis the width of the limbs, which exceeds anything that I have seen.
Back to the question: what if I had been right?
My view: it would not have been a bow with two working parts to each limb; but a bow with two working limbs with a useless bit of sold wood adding unecessary weight in between them.
What is of much greater interestis the width of the limbs, which exceeds anything that I have seen.
But would it be totally wrong if bow had two working parts?
We been told that a Turkish bow should bend a little at the kasan eye. Can it be done more accurate? Say limbs bend to 80 lb and then the kasan eye starts to straighten. It would give longer power stroke, or?
We been told that a Turkish bow should bend a little at the kasan eye. Can it be done more accurate? Say limbs bend to 80 lb and then the kasan eye starts to straighten. It would give longer power stroke, or?
It an`interesting question. A bow with two bending parts would have the high string tension at brace = high early draw weight. But the transition to the onset of bending in the second part would be gradual, not abrupt, so the resulting f-d curve would not differ much from a bow with totally rigid siyahs. Actually I would expect such bow to stack earlier in the draw for less energy storage. It is beacause the second bending part is higher up in the limb and closer to the tips. A bow with bending more concentrated towards the grip will store more energy.
Adam
Adam
Wow ,how do you get a horn strip that wide ? or was it side by side strips on each limb? And do you have any idea what that bow's draw weight was ?
It was five strips of horn. The draw weight of the exact reproduction was 50 lbs at 30"
S
S
Are there any pictures of the reproduction?
Mr Selby
Is it possible that a draw of longer length was used? The bow is quite long in length it seems at 162 cm, maybe they drew it to 34? I don't know, but it seem it would get more out of such design.
Is it possible that a draw of longer length was used? The bow is quite long in length it seems at 162 cm, maybe they drew it to 34? I don't know, but it seem it would get more out of such design.
I have had my thought about that to, why put in so much effort in a bow that just draws 50 lb. It can be done with almost any stick.
A wood bow in the Taklamakan desert would be most unreliable. A #50 bow tested in HongKong might be a different animal in the desert. It would only have to be slightly better than your enemie's. -j-
Mr. Farrell
That is good point, I did not think of that!
Gansu would be very dry indeed, almost impossible for local woods to be durable, or at least more durable than a horn bow.
Though, I still believe this design could be taken a bit further. The wide limbs seem to be designed for lesser stress and the length would seem to lend itself to long draw.
Also, as you say the climate varies quite a bit between the two places. Right now, the humidity in Hong Kong is 92% while its only 15% in Gansu. Quite big difference, it equals to 21.6 EMC in Hong Kong while being as low as only 3.6 EMC in Gansun. At this level, I think the hickory would even fail. This would also make the sinew shrink much more, and make the bow much stiffer. Perhaps we would see some rise in draw weight, maybe 30#? more? I cannot say, I don't know enough about moisture change or the bows of composite.
That is good point, I did not think of that!
Gansu would be very dry indeed, almost impossible for local woods to be durable, or at least more durable than a horn bow.
Though, I still believe this design could be taken a bit further. The wide limbs seem to be designed for lesser stress and the length would seem to lend itself to long draw.
Also, as you say the climate varies quite a bit between the two places. Right now, the humidity in Hong Kong is 92% while its only 15% in Gansu. Quite big difference, it equals to 21.6 EMC in Hong Kong while being as low as only 3.6 EMC in Gansun. At this level, I think the hickory would even fail. This would also make the sinew shrink much more, and make the bow much stiffer. Perhaps we would see some rise in draw weight, maybe 30#? more? I cannot say, I don't know enough about moisture change or the bows of composite.
I see, environment. Can make big difference. How does a hornbow like temperature below freezing?
As I understand it backed bows do better than horn bows in freezing weather. -j-
A few things -
I asked for the bow to be made to about 50#. I expect it could have been made heavier; but a visual inspection suggests that it is very close to the original.
Climate does of course affect performance. Mainly temperature. That Khotan bow was used in an area that sees a tamperature variation of +40C to -25C. (I myself have been at the point it was excavated, both at +50C in summer sun and -19C in the winter. The altitude is -60 metres pd.) The Mongolians tell be that extremely dry conditions harm bows; they go to some lengths to keep some moisture in the bow.
So if you ike the idea of long siyahs and you have such variable environmental conditions, then to keep stability, behaps extra-wide limbs are the way to go.
S
I asked for the bow to be made to about 50#. I expect it could have been made heavier; but a visual inspection suggests that it is very close to the original.
Climate does of course affect performance. Mainly temperature. That Khotan bow was used in an area that sees a tamperature variation of +40C to -25C. (I myself have been at the point it was excavated, both at +50C in summer sun and -19C in the winter. The altitude is -60 metres pd.) The Mongolians tell be that extremely dry conditions harm bows; they go to some lengths to keep some moisture in the bow.
So if you ike the idea of long siyahs and you have such variable environmental conditions, then to keep stability, behaps extra-wide limbs are the way to go.
S
Yes. See attachment.Orda Khan wrote:
Are there any pictures of the reproduction?
Hi! My question is off topic, but I'm interested how much did Grozer charge you for making replica. I sow on his site that his hornbows are 800-1000 euros, but he probably charge something extra for special orders. Thanks
I hope you would understand that I wouldn't reveal that. He is sometimes interested in a technical project for its own sake, which can affect what he decides to charge. You would need to get the answer from him.
S
S
Thanks anyway, I will contact him, but before that, I have lots of work on finding the most interesting and characteristic bow from my country to be reconstructed. And to spare money of course.