[Gary T]

Interesting on the flatbow, Timo, I was not that familiar with them.

I'd guess the "inferior woods" would make it generally a lower poundage bow, and undoubtedly less efficient.

I wonder how the performance of a flatbow compares to a corresponding D-shape bow.

[Philip Dyer]

[Timo Nieminen]

For a bow drawn by human muscle in the usual manner of a bow, there's a limit to how high the draw weight can be. Since the stored energy is approximately (1/2)*(power stroke)*(draw weight), where (power stroke) = (draw length)-(brace height), once you reach that limit of manageable draw weight, then your energy becomes proportional to draw length.

For a regular bow, if you want to maximise energy, you maximise draw length. (This doesn't come without cost - you take a hit to accuracy, and you might not gain any range (or even lose range), so you don't do it unless you are serious about getting that energy. A similar thing can be said about draw weight.)

For a crossbow, where mechanical aids are available, short draw length and high draw weight can work. But that's not really relevant to a regular bow. (The Chinese approach to high-energy crossbows was to use long prods and long draw lengths.)

[Gary T]

[Glennan Carnie]

In case this hasn't been posted before:

https://www.youtube.com/watch?v=0-2KLuAH4GY

Joe is possibly the closest we've got to a medieval archer as he's been shooting 100lb+ bows since he was a teenager. Those who have shot with him will confirm he is as accurate with a 160lb bow as most other archers are with 80lb, so it's a fallacy to think a powerful bow precludes accuracy.

Interestingly, Joe has said his draw length is limited (to about 32") by the compression across his skeleton from the really heavyweight bows.

[Gary T]

[Will S]

Marks probably closer than you think to a "normal" medieval man.

I personally think it's a bit of a myth that they were badly fed, weak, unhealthy and small - especially if you consider the household and royal archers. Medieval life was hard working, active and involved. No sitting around watching TV, staring at phones and answering emails like today. I would imagine that Mark wouldn't look out of place in the 1400s. In person he's not particularly large - there are bodybuilders out there far bigger than him who couldn't pull a bow of 100# let alone 180#.

I think too much emphasis is placed on the numbers when talking about draw weight - no matter who you are, if you've spent years practicing with a bow of 150# you'll be just as accurate as somebody who's spent years practicing with a 50# bow. The fact that less people consider training with a medieval Warbow than a 50# target bow is more relevant to the lack of archers capable with a very heavy bow than the weight itself, in my opinion.

It might also be worth noting that up until recently bow weights of more than 100# were considered extremely hard to shoot. Today there are exceptionally talented guys like Joe, Mark and Glennan who are shooting over 150#. Mark still holds the world record at 202# but with Joe already pushing 185# and still in his 20s who knows what he'll be able to achieve.

[Timo Nieminen]

Higher arrow speeds improve accuracy. Everything else being the same (especially the efficiency of the bow), higher draw weight gives you more arrow speed. Which is why Olympic archers shoot bows of relatively high draw weight for modern target bows.

Once the draw weight approaches the limits of what the archer can comfortably manage, then the archer
(1) won't be able to hold the bow steady at full draw for aiming
(2) will get tired faster (and therefore will shoot fewer arrows in training), and
(3) when tired, might not get to full draw.
But until you get to that point, higher draw weight generally gives better accuracy.

Which is not to say that one can't be accurate with a 150lb bow. But an archer who can draw a 150lb bow at most will probably be more accurate when shooting a 100lb bow; to be most accurate with 150lb, one might want to be able to handle 200lb. (I've seen quite a few people claim best accuracy at about 80% of the highest draw weight they can manage; that's doesn't seem like a bad estimate to me (though it depends on the standards of that "manage" for the highest draw weight).)

[Gary T]

[Philip Dyer]

[Gary T]

[Benjamin H. Abbott]

The numbers from other regions can possibly help fill in our understanding of how much historical archers could draw. A seventeenth-century Ming Chinese source says that strong archers drew 158lbs, average archers 126-142lbs, weak archers 79lbs, and very strong archers more than 158lbs. It's not clear in the text, but this was almost certainly for infantry archers given the weights. In eighteenth-century China, only relatively small numbers of troops at the less-experienced garrisons successfully tested with bows heavier than about 130lbs. At Hangzhou in 1736, only 80 soldiers out of 3,200 passed examination with 145-172lbs. Of course, that percentage was likely higher at the better garrisons in the north and perhaps in earlier times. And it's unclear how to compare such different numbers, given different bow styles and standards of practices, etc.

However, in my view the weight of the evidence suggests that quality infantry archers typically drew 130-160lbs while quality mounted archers managed 90-120lbs. A small number of especially strong archers drew more than 160lbs on foot or 120lbs while mounted and still shot effectively.

[T. Kew]

[Timo Nieminen]

A good summary is that if you double the draw weight of the bow, and double the weight of the arrow, you'll get double the energy (and therefore shoot that double-weight arrow at the same speed). Keep the arrow weight the same, rather than doubling it, and that arrow will come out a little faster out of the bow (assuming that the efficiency, for the same arrow grains per pound, is the same). Not much faster, but still faster. If you double the draw weight and double the mass of the limbs, you'll keep that efficiency for the same gpp the same. (If you dry-fire the original and the double-weight bow, the limbs will move at the same speed. Double the mass but double the force moving them.)

Actually, you can do better than that. The stiffness of the bow is proportional to the thickness cubed, so as long as you aren't near the elastic limit of the bow, you can double the draw weight without doubling the mass of the limb. This means that even though the mass of the limbs increases, the draw weight increases by more, and the efficiency of the bow, for the same arrow grains per pound, increases. (If you more than double the weight of the limbs when you double the draw weight, it isn't a good design. If you keep the thickness of the limb the same, and double the width of the limb, you should get double the draw weight and double the limb mass. If you're at the elastic limit of the material, you have to go wider or longer. Offhand, I don't know how longer scales, but wider is simple.)

But yes, the increase in velocity won't be very big. The speed at which the bow can move its own limbs does limit the maximum velocity, and a light arrow will be moving at close to that velocity already. But a little more speed, a little closer to that maximum velocity, can be achieved. But for that little increase in speed, you incur the penalties of the higher draw weight, so that increase might not be worthwhile. Which likely contributes to why top-level target archers stop at about 50lbs draw. Basically, your "plateau where the arrow is light enough relative to the bow's draw that it's essentially irrelevant" has been reached.

[Gary T]

Benjamin H. Abbott wrote:

[Timo Nieminen]

As a mounted archer, you don't always have your body in the ideal position (that would be shooting directly to the left, at 90 degrees from your horse's head). The angles you can shoot at (at full draw; more than this if you draw short) are from the left of your horse's head to over the tail, but I think that the angles where you are more twisted around will stop you from using as high a draw weight bow as straight-to-the-left.

(You also want to be able to change hands and shoot to the right, or, as a Chinese writer advised, be able to turn your horse around very quickly.)

Ancient Persians (as in Persian-Greek wars Persians) used the Central Asian composite bow.

[Gary T]

[Benjamin H. Abbott]

Various sources suggest cavalry bows had significantly lower draw weights. The Chinese-region military exams recorded in Stephen Selby's Chinese Archery have cavalry draw weights at 55-74% of infantry draw weights. These are from the eleventh through thirteen centuries and go as high as 167lbs for first-class infantry bows. Of course, bows for the battlefield weren't necessarily as heavy as ones for the exam, but these exam records give us a sense of the ratio between infantry and cavalry bows. Beyond such figures, an eighteenth-century proclamation from one of the Qing emperors mentions how it's difficult to use a hard bow on horseback. Finally, reconstructions and estimates of extant pieces suggest an average weight of around 100lbs for a number of different types of composite bows, many or all of which were used while mounted. (Surviving Turkish bows surveyed by Adam Karpowicz average 111lbs.) Roughly 80lbs (a strength rating of six in Qing terms) was apparently the minimum for competent Manchu mounted archers, with elite mounted archers drawing 130+lbs on hunts (not necessarily in combat, though quite possibly so).

[William P]

regarding cavalry bows against infantry bows and crossbows

i recently recorded a video about me talking about the crossbow, and how (according to some discussions on myArmoury) suggesting that the steps and systems in place to train and effectively deploy crossbows laid the groundwork for drill and deployment of firearms like the arquebus and musket

in the same video i talked about the use of crossbows supported by sergent spearmen in the 3rd crusade to keep horse archers at bay

is it accurate to perhaps say that crossbows would have been able to outrange horse archers and keep them at a distance, stopping them from riding closer to a target to shoot their arrows at closer ranges (almost like a carocle)

on that note, is there much reference to crossbowmen firing in mass volleys in a similar way as musketeers?

and lastly is there any evidence of companies of mercenary crossbowmen possessing a small percentage of very high capacity crossbows for targeting more heavily armoured targets?

i realise some of this is speculation however and im not sure what was feasable.

[Gary T]

Well, I'd say you certainly provided some good backup documentation, Ben.

I have heard, but not sure of the veracity of this that Mongol archers used heavier bows than the turkish type bow. Any truth to this that you are aware of? Could possibly even mean a heavier arrow perhaps.