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190 fps at 15 gpp!

5K views 58 replies 14 participants last post by  wseward 
#1 ·
"The 82# Manchu bow, made by Wen Chieh, outperformed a well-made 128# yew longbow, shooting the same 1230 grains (80g) military weight arrow a stunning 190fps against 170fps for the longbow."

The devilish details at:

http://www.manchuarchery.org/bows
 
#7 ·
Cool article, thanks for posting.

This is the line that really caught my attention...

"The champion in a 1728 contest between the one hundred top bowmen in the empire won one hundred taels when he hit the bull's-eye using an eighteen-strength bow an estimated drawing weight of almost 240 pounds!"

:weightlifter: :faint:​
 
#9 ·
The composite, static tip recurves were known to the western Europeans. Roman troops/auxillaries used them all through the empire in Britain, Gaul (France), Germania, and Hispania (Spain). When the empire fell, the bows went w it. Eastern Europeans kept using them though. There are economic/tactical/logistic reasons to prefer a wooden self longbow. They are easier, quicker, and cheaper to make, less bothered by extremes in temp and humidity, and easier to take care of string at heavy weights, etc.

240 lbs!? It's amazing what archers did when it was a matter of life and death, not just fun and games? ;)
 
#26 ·
240 lbs!? It's amazing what archers did when it was a matter of life and death, not just fun and games? ;)
I wonder if that guy's last name was "ballista" :)

It is really interesting to think there was probably no counter-measure for these warbows... the light bows of asian and muslim archers I always thought were just as effective (speed kills) but then I read this:

Saladin’s secretary Beha al-Din, had a very different take on the effectiveness of muslim arrows against the crusaders. He writes that "Their infantry, drawn up in front of the horsemen stood as firm as a wall, and every footsoldier wore a thick gambeson [padded jacket] and mail hauberk so thick and strong that our arrows had no effect. I saw soldiers with from one to ten arrows sticking in them still trudging on in the ranks."
 
#12 ·
How do you string that thing up?
Very carefully! A slip could result in serious injury w the heavy bows. This limb design is very susceptible to twisting, and if it twisted enough to unstring, serious injury and death could be the result. Stringing could be a two man operation, or special wooden blocks (gong nazi) or peg boards would be used to bend and hold the limbs in increments until fully strung. For the adventurous, a modified step-through w the lower limb on the thigh, pulling the upper limb down, and placing the loop on the lower limb. See: http://www.manchuarchery.org/content/composite-bow-care-and-maintenance
 
#13 ·
This is probably what Sid was talking about with a super-recurve. What happens is that at brace you're pulling the recurves straight back (making for a very short bow that's very stout, hence the massive increase in weight right off of brace), but as the recurves open up, you suddenly have a ton of leverage (so the longer the siyahs... the better leverage) which makes the bow suddenly butter smooth at full draw. Hence, tons of stored energy. If the siyahs are light enough (or here, you use a heavy enough arrow) all of that stored energy turns into delivered energy.

So, if we could figure out how to deal with that twisting trouble, we could have a 40# bow that shoots a 600 gr arrow at 190 fps... that's more power than my 55# bow...

I have some building to do!!!
 
#14 ·
So, if we could figure out how to deal with that twisting trouble, we could have a 40# bow that shoots a 600 gr arrow at 190 fps... that's more power than my 55# bow...

I have some building to do!!!
Yeah, that's what I want! And I want it in a 56 inch bow at 28 inches... ;)
 
#17 ·
BrokenArrow, you have created a monster...:lol:

I'm going to give static tipped, ultra reflexed longbow limbs a shot first. My current longbow is delivering about 39 KE with a 50# bow and a heavy arrow. The current design only has an inch or so of reflex, and the tips aren't perfectly stiff (flexible tips increase vibration and lower efficiency). If I laminate a wedge into the ends of my Delta Shortbow limbs, I should also be able to lighten the tips up... a lot. The DS limbs on my longer riser will make a 66"-68" bow with about 6" of final reflex. Should be a lot easier to keep straight than a recurve, and hopefully the stiff outer limbs help with the flip-floppy limb issue.
 
#21 ·
Impressive design, to be sure. Shows that some people were really smart way back when :)

Certainly an implementation of high energy storage, and with heavy arrows, a fantastic 95% dynamic efficiency...

Keep in mind, though, that they're doing a 32" draw. Not really an apples to apples with a 28" draw comparison...
 
#22 ·
More like Macintosh v Red Delicious? ;)

Found this for longbows drawn 32 inches:

"The Great Warbow" - Matthew Strickland and Robert Hardy

210fps at 5.5gpp, 340 yds
190fps at 7.6gpp, 280 yds
175fps at 9gpp, 250 yds

150# bow at 32 inches

Which is close enough to the 170fps/1230g/128lb/9.6gpp for the longbow in the Manchu link.

Then again, this is one test of a Manchu bow; don't know if can/has been repeated/verified w other bows by other people.
 
#28 ·
Very interesting............... and made more interesting by the quality commentary.

I see that ancient bow and wonder how the discussion went way back when, "Emperor, The archers are ready for battle....would you like the good news or the bad news first"
"Well Emperor these bows are incredibly efficient................but almost 1/2 of our archers are seriously injured while attempting to string them"
 
#31 ·
could be LOTS of things.
but an increase in BH gets rid of it.

A change in former profile also does the same. More aggressive limb angles at the fadeout can help.

or one fade out is stronger than the other. ie the source of the tiller is not even on both limbs.

but these can be the main sources.

weakening the outer limb by traping is can simulate the higher BH, BUT it does depend on the source of the problem

all this is in our experience... others might have different answers...

Is this for a Takedown longbow limb?
 
#37 ·
Ive borrowed a couple of photos from someone else here... but as you can see, we have made thick ILF limb butt at the rockers. to kick the limb forward, making the best of a bad angle. Longbows don't like recurve geom...






With ILF there are two places of contact, under side of the bolt. and the rocker. You either need to wind the bolts in, or push the rocker out... we did the latter.


This reduces the needed BH. without giving you a horrible limb shape needed to get the energy up.

At least that's our thinking.

We don't have any limbs with any glass in them. so the limbs are light, but adding mass at the limb butt isn't a problem...
 
#41 ·
ok, preload, is how far the limbs travel from unstrung to strung,

so with this understanding.
the reflex in the limb (forward pointing) casues the limb to flip flop back and forth. (take any reflex/deflex limb design, and drop the BH to 3" and it will flip top to bottom in a horrible way)
so with heavy limb pad angles. (pointing the limbs at the archer) that you see on recurves. such as the Bear riser. the longbow limb points soooo far back. that you need a high brace height to give enough preload to open up the reflex. (straighten the limb out)
so if you point the limb forward at the limb pocket, you can preload the limb more, but still have a lower Brace height.

So the limb straightens up.

if you look at all hybrid/R/D bows, the limbs come dam near straight out the riser.
if you look at recurves, the limbs are slopped back to the archer.
These two aspects don't mix.

Kegan (I think) has been struggling to get a lower BH, to become stable due to poor preload of the slack angles. giving a floppy bow.
If he increases the BH, he chokes off the energy in the bow. giving poor performance.

kick the limbs forward more, and you get a solution that works better.

You cant do that with the limb angle due to the need to run a recurve limb, so our solution was to thicken up the limb butt rocker. as per the pictures.
This still gives a Longbow limb but its more forward pointing. and this means that the lower BH still has the preload, without killing the limb shape.

a bow needs to look right, it needs to perform well, and it needs a simple solution to the problem.

That's the most simple we could come up with.
 
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