Originally Posted by fearn
I suspect you're overgeneralizing a bit. Certainly, !Kung and Pygmy bows are weak. However, there are reports of Liangulu "Elephant bows" that pulled over 100 lbs. Saxton Pope, a prominent English Archer, visited Kenya in 1925. He challenged a Wakoma archer to a friendly distance contest. Pope at first used a yew longbow and a (light) flight arrow. The Wakoma outshot him, using his hunting bow and a heavy hunting arrow. Pope then switched to the heaviest bow he owned, and managed to outshoot the Wakoma (still using his hunting rig) by ten paces, at which point he called a halt to the contest. (Traditional Bowyer's Bible, vol. 3, which is most of what I know about African bows).
I'd say that, before WW2, there was as much diversity in African bows as there is in North American bows. There were big bows around. We're just lacking samples for this website. So far.