The Mongol bow is generally considered to have a draw weight of around 75kg (166lbs)[1], while the American bow was around 30kg (70 lbs)[2], which was much more comparable to most other horse-mounted archers.

The English longbow was estimated to have a draw weight of between 45kg and 82kg (100lbs to 180lbs)[1] but of course was much bigger and couldn't really be used on horseback.

[1] https://interestingengineering.com/lists/the-most-powerful-b...

[2] https://centerofthewest.org/2017/07/21/plains-indian-weapons...

It should be noted that the composite bow is not a new invention, even if the knowledge about how to make them appears to have been lost in many places.

In the Homeric poems, Iliad and Odyssey, composite bows are described, e.g. used by the very skilled archer Odysseus.

Moreover, even older descriptions (from the second half of the second millennium BC) of composite bows can be found in the myths preserved on the tablets from Ugarit.

I am not sure where you are getting the 166 lb figure from.

It is true that an Asiatic composite bow over a certain draw weight (depending on design) can impart greater energy on the arrow than a self-bow (long bow) of the same draw weight. The force-draw curves are different, and some of these bows have very long draws in comparison.

I gave a reference for where the 166 pounds came from. Search for 166 on that page.

I see references to George Vernadsky, but no details on which history contained this information, nor how Vernadsky derived the 166lb figure. I am not even sure if he is measuring pre-17th Century Mongolian bows, since post-17th Century, Mongolian bows were influenced by the Manchu designs.

The site the interestingengineering references, itself does not contain references. There are odd discrepancies, such as the section on stringing the bow. Past a certain draw weight, you can no longer string the bow using the one leg or sitting method. The Manchus used equipment off the horse to string their bow, and kept them in cases while strung, to protect them.

No contest - the Mongols were rightly feared as murderous scorched earth invaders (at least for those that didn't immediately surrender and get incorporated into the Mongol host).

If you mean with same-era technology, the answer is they

Europeans did not bring horses to America until after the Mongol empire had already collapsed, so the people there (whether called Comanches, Shoshone, etc.) couldn't even have any horseback archers. :P

... I have no idea how that first sentence got cut off while editing. I was quite sure it was correct the last time I hit "update."

"would have fared Very Badly (or perhaps Not Applicable.)"

It's always hard to compare across different tech levels. If you're talking about 19th century Comanches, they have the advantage of having access to rifles.

Without that, I think the Mongols would easily win. They had a huge army that rapidly conquered the largest contiguous land empire ever. They had powerful bows, better armour, very effective tactics, but they were also excellent at sieges. Every country they conquered, they assimilated the best ideas and technology they had, which made them able to shift to very different types of warfare. They were capable of strategic maneuvering on a scale that wouldn't be seen again until WW2.

Their weakness was primarily in their rules for succession. If the death of a leader requires you to abandon all campaigns and moving all generals to the capital, after which the empire still fragments into several pieces, that's a bit a of a problem.

A friend has a mongolian horseman bow. He shot a birch tree 75 yards away, and the arrow went in nearly an inch. I knew they were powerful, but I didn't know they were that scary powerful.

I once read that Edward I ordered the English to practice with longbows after he saw a longbow shoot through a heavy oaken church door in Wales. It's crazy how powerful a good war bow can be. Nothing like modern sports archery.

Wait until you see a Manchu bow in action.

Might depend on how many viruses were dormant in the Comanche population.