a monster Krim-Tatar
I am working on a super heavy Krim-Tatar bow, to be sent to the UK, shot by Joe Gibbs and compared with the yew warbows there. I am curious how it turns out and if Joe, and hopefully other heavy weight archers like the performance.
Specs:
180lb at 31.5 inch draw, about 54in ntn, 7in brace, 18.9g string made of flax. Not much grip reflex.
Two shots (60%RH, 20degC for the last few weeks):
63.9g (984 grain, "livery" weight) arrow - 249fps
115.4g (1777 grain, a bit over 1/4# arrow) - 188fps
This is not bad considering the string is quite heavy, but the longer draw helps. What I find interesting is the efficiency of the bow. It stores enormous amount of energy, a little over 190ftlb (260J) thanks to the long draw, but the efficiency is average (compared with the Turkish bows) of roughly 71% for both shots. Note one shot was at 5.5gpp, the other at almost 10gpp. This is of course a fresh bow, so these numbers may go down a little with time.
i now understand why the ramie strings on the Tatar war bows were served over the whole length. It is because the strings whip so much on release that the threads break one by one on every shot. It never happened with silk strings.
This one might be the last of the monsters. The other one was a bow I sent to Alan C. to be shot as a footbow at the Bonneville salt flats, but unfortunately it could not happen this year. It is so much easier to make sub-120lb lightweights.
Adam
Specs:
180lb at 31.5 inch draw, about 54in ntn, 7in brace, 18.9g string made of flax. Not much grip reflex.
Two shots (60%RH, 20degC for the last few weeks):
63.9g (984 grain, "livery" weight) arrow - 249fps
115.4g (1777 grain, a bit over 1/4# arrow) - 188fps
This is not bad considering the string is quite heavy, but the longer draw helps. What I find interesting is the efficiency of the bow. It stores enormous amount of energy, a little over 190ftlb (260J) thanks to the long draw, but the efficiency is average (compared with the Turkish bows) of roughly 71% for both shots. Note one shot was at 5.5gpp, the other at almost 10gpp. This is of course a fresh bow, so these numbers may go down a little with time.
i now understand why the ramie strings on the Tatar war bows were served over the whole length. It is because the strings whip so much on release that the threads break one by one on every shot. It never happened with silk strings.
This one might be the last of the monsters. The other one was a bow I sent to Alan C. to be shot as a footbow at the Bonneville salt flats, but unfortunately it could not happen this year. It is so much easier to make sub-120lb lightweights.
Adam
Adam, very interesting (all of it, but one thing is especially on my mind these days): It would be an indication that the Dresden strings are genuine.Adam Karpowicz wrote:
i now understand why the ramie strings on the Tatar war bows were served over the whole length. It is because the strings whip so much on release that the threads break one by one on every shot. It never happened with silk strings.
David Betteridge and I have been thinking about fully served strings for several years. They have greater stiffness than normally served strings and seem to behave much like a heavier string without the penalty of the extra mass. The mass of the serving can be reduced by using small diameter thread.
Individual strands breaking sound more like a string without the strands at even tension. The ramie I have dealt with has been very smooth and silky feeling. This may be the result of processing since it was not particularly strong.
The Uzbek silk that used to be sold by Aurora is very strong but it hasn't been twisted tightly in manufacture and needs stretching to be efficient.
I am worried about the ramie strings in German collections. The one in Karlesruhe is completely in the Qing tradition, despite its size, and the Dresden ones look like the strings for "monkey" bows. However, they seem old and the evidence from the Vienna booty is that there were Qing artefacts in the Turkish army (e.g. a black Manchu quiver and a Chinese woman's shoe).
Individual strands breaking sound more like a string without the strands at even tension. The ramie I have dealt with has been very smooth and silky feeling. This may be the result of processing since it was not particularly strong.
The Uzbek silk that used to be sold by Aurora is very strong but it hasn't been twisted tightly in manufacture and needs stretching to be efficient.
I am worried about the ramie strings in German collections. The one in Karlesruhe is completely in the Qing tradition, despite its size, and the Dresden ones look like the strings for "monkey" bows. However, they seem old and the evidence from the Vienna booty is that there were Qing artefacts in the Turkish army (e.g. a black Manchu quiver and a Chinese woman's shoe).
That sounds great Adam! Looking forward how could thay handle that weight on a hornbow :wink:
Hope will post some pics and more specs from that monster....
Bede
Thats a usefull information for me from silk.
http://www.aurorasilk.com/silk_yarns/index.html
Could you tell us exactly what product have tried from tham?
Thanks!
Hope will post some pics and more specs from that monster....
Bede
Thats a usefull information for me from silk.
http://www.aurorasilk.com/silk_yarns/index.html
Could you tell us exactly what product have tried from tham?
Thanks!
Aurora stocks certain silks as they are available. The closest silk currently available is their reeled hand sewing silk. http://www.aurorasilk.com/silk_yarns/hand_sewing.html
This silk is very similar to the silk I have in an original Turkish bowstring. They have another reeled silk for machine sewing:
http://www.aurorasilk.com/silk_yarns/ma ... ewing.html
This is suitable for very fine serving, though you do not need a silk as strong as this. It can be made into bowstrings if you want a very high thread count. Making strings with thread as fine as this is very difficult. The thicker, 84 denier, silk is more appropriate.
The description "reeled" means that it is made from continuous lengths of fibre reeled from silkworm cocoons. These are twisted together to make threads. This is also called filament silk. The fact that it is twisted rather than spun means it has some unusual behaviours when not under tension. It can tie itself into knots while you are looking at it.
This silk is very similar to the silk I have in an original Turkish bowstring. They have another reeled silk for machine sewing:
http://www.aurorasilk.com/silk_yarns/ma ... ewing.html
This is suitable for very fine serving, though you do not need a silk as strong as this. It can be made into bowstrings if you want a very high thread count. Making strings with thread as fine as this is very difficult. The thicker, 84 denier, silk is more appropriate.
The description "reeled" means that it is made from continuous lengths of fibre reeled from silkworm cocoons. These are twisted together to make threads. This is also called filament silk. The fact that it is twisted rather than spun means it has some unusual behaviours when not under tension. It can tie itself into knots while you are looking at it.
Thanks for the informations!
For me it looking the 21 denier thicker than 84 which is the finest one.
The Barbour linen have something simillar numbers so the higher noumber is the finer thread.
For me it looking the 21 denier thicker than 84 which is the finest one.
The Barbour linen have something simillar numbers so the higher noumber is the finer thread.
very interesting. thank you for posting.
thats a valuable theory about the string serving. and manchu bows were also of heavy draw weights. the provenance of the strings remains mysterious though. maybe we will find similar ones in other collections ;-)
thats a valuable theory about the string serving. and manchu bows were also of heavy draw weights. the provenance of the strings remains mysterious though. maybe we will find similar ones in other collections ;-)
That bow does indeed sound like a monster! Please can we have some pictures :shock:
This is going to be fun. If it gets to be shot properly it is going to be very difficult to beat. :shock:
I'm not able to wrap my mind around what it means that its efficiency is the same for both arrows. Strange.
Too bad the Turkish bow did not get to be shot in Utah. Hope it will happen next year. I'm curious, did you speed-test that bow as well? Any higher than the 357 fps from 2005?
I'm not able to wrap my mind around what it means that its efficiency is the same for both arrows. Strange.
Too bad the Turkish bow did not get to be shot in Utah. Hope it will happen next year. I'm curious, did you speed-test that bow as well? Any higher than the 357 fps from 2005?
Here is the picture - strung and unstrung.
The strings for "monkey bows" (as I recall from the Chengtu article) were made as endless strings. Endless strings of flax break on the first shot, because the loops are half the thickness of the main section. The strings in Dresden are not endless - the loops are the same thickness as the main. When made that way, they work well on even the heaviest bows. I am not sure if flax is a better material then silk for these bows, but perhaps flax can maintain some resistance in wet weather, so it could be used for European campaigns.
The bow for the flight shoot was 150lb at 26in. I shot it during tiller when it was still about 200lb, but never measured the speed.
Adam
The strings for "monkey bows" (as I recall from the Chengtu article) were made as endless strings. Endless strings of flax break on the first shot, because the loops are half the thickness of the main section. The strings in Dresden are not endless - the loops are the same thickness as the main. When made that way, they work well on even the heaviest bows. I am not sure if flax is a better material then silk for these bows, but perhaps flax can maintain some resistance in wet weather, so it could be used for European campaigns.
The bow for the flight shoot was 150lb at 26in. I shot it during tiller when it was still about 200lb, but never measured the speed.
Adam
Hi folks
Just wanted to ask is Joe going to shoot this bow with a three finger technique in an English Longbow ( war bow ) style or is it going to be a thumb draw attempt ? I'm assuming three fingers.
Also ( slightly off topic ) what is the maximum draw weight anyone has drawn with a thumb draw ?
Mark Stretton claims 200lbs for a longbow Joe Gibbs is not far off, another guy called Den Erickson claims a further 30lbs more than Mark at 230lbs this claim is hotly disputed though. Guys in the English War bow Society regularly shoot 100lb plus bows ( 70lb is an absolute minimum requirement just to join ) But all of this is done using three fingers.
Anyone know of regular war bow weight shooters with a thumb draw and at what weights ? bow type etc..?
Just wanted to ask is Joe going to shoot this bow with a three finger technique in an English Longbow ( war bow ) style or is it going to be a thumb draw attempt ? I'm assuming three fingers.
Also ( slightly off topic ) what is the maximum draw weight anyone has drawn with a thumb draw ?
Mark Stretton claims 200lbs for a longbow Joe Gibbs is not far off, another guy called Den Erickson claims a further 30lbs more than Mark at 230lbs this claim is hotly disputed though. Guys in the English War bow Society regularly shoot 100lb plus bows ( 70lb is an absolute minimum requirement just to join ) But all of this is done using three fingers.
Anyone know of regular war bow weight shooters with a thumb draw and at what weights ? bow type etc..?
It looking great Adam!
How thick and wide the horn on it? Glued it on to flat or crowned core?
What kind of flax have used for that string and how thick is it?
One of the best machine made flax was the Irish made Barbour but the factory sold and the EU made Barbour is much weaker. Anyway all of tham contains abot 5 inch parts so it have to be weaker of a string made from full long plant fibers.
In your book sad use flax just for sub 60# bows. Now to see it on this bow surprised me.
How thick and wide the horn on it? Glued it on to flat or crowned core?
What kind of flax have used for that string and how thick is it?
One of the best machine made flax was the Irish made Barbour but the factory sold and the EU made Barbour is much weaker. Anyway all of tham contains abot 5 inch parts so it have to be weaker of a string made from full long plant fibers.
In your book sad use flax just for sub 60# bows. Now to see it on this bow surprised me.
I am sure Joe will shoot with 3-fingers. As far as I know there are people drawing over 100lb with the thumb (Gokmen for example), perhaps even much higher, possibly with long-draw bows.
The horn was glued flat, but is round on the outside as usual. I think it is about 8mm thick mid limb where the total thickness is about 17mm and the width 38-9mm. If the bow had more setback at the grip, the limbs could be made a little thinner than that. I wanted less setback, since it is a real struggle to string the bow without the tepeliks and a bow press (Joe will be using a peg board).
The string was made of Barbour flax thread and the total thickness was 4mm. This is a different type of string I did not know when writing the book. At the time, I used endlesss and separate loop flax strings - all were breaking one by one!
Adam
The horn was glued flat, but is round on the outside as usual. I think it is about 8mm thick mid limb where the total thickness is about 17mm and the width 38-9mm. If the bow had more setback at the grip, the limbs could be made a little thinner than that. I wanted less setback, since it is a real struggle to string the bow without the tepeliks and a bow press (Joe will be using a peg board).
The string was made of Barbour flax thread and the total thickness was 4mm. This is a different type of string I did not know when writing the book. At the time, I used endlesss and separate loop flax strings - all were breaking one by one!
Adam
Wow thats a huge size :)
Sorry for the string OFF questions but working on this right now.
So We have the same stuff, may just the size different.
I've got 3/35 and used it for wooden bows before. It have a 4.5kg breaking strenght on a 1m long piece. Alan Case sad this Irish Barbour is the best modern flax thread he tested.
For me the 4mm sounds under the lowest limit on this draw weight. It schould be about 4 times stronger than the draw weight. I estimate a 5.5 mm string would be safer with knots on it, but I'm shure you've mesured it. Think it made for just a few fligt shots isn't it?
If I understand well, you've made a string like on old mongol bows. Full lenght the same dia. and the loope made with knot?
Or spin it back to itself like on flemish strings, without knot? The pic is too small to see it.
Sorry for the string OFF questions but working on this right now.
So We have the same stuff, may just the size different.
I've got 3/35 and used it for wooden bows before. It have a 4.5kg breaking strenght on a 1m long piece. Alan Case sad this Irish Barbour is the best modern flax thread he tested.
For me the 4mm sounds under the lowest limit on this draw weight. It schould be about 4 times stronger than the draw weight. I estimate a 5.5 mm string would be safer with knots on it, but I'm shure you've mesured it. Think it made for just a few fligt shots isn't it?
If I understand well, you've made a string like on old mongol bows. Full lenght the same dia. and the loope made with knot?
Or spin it back to itself like on flemish strings, without knot? The pic is too small to see it.
Since the Dresden strings may have been made this way, this is very interesting!Adam Karpowicz wrote:
This is a different type of string I did not know when writing the book.
Any hints where to find more info about this specific kind of string? How does one achieve it that the string looks like endless, but the loops come out with the full diameter instead of 50%? A stacked array of threads?
Adam - has this bow got to it's new owner yet? If so you do you know the results of shooting it?