I have been messing around with these two currently, they are my sole backing materials at the moment. I trust my maple I got way more than my bamboo, but apparently bamboo is regarded as a much better backing than maple. I find the maple much more predictable though. WAY cheaper too, and a lot less work.
When bend testing it, it seems pretty decent. Not like good hickory, but still good. The piece I got is denser and not very porous at all. I am wondering about going over 100# or so with either in an elb design. I just had a shorter r/d bbi break on me, the bamboo splintered on each limb. I think it might of been too heavy and deep with too weak/thin a backing, and too reflexed, etc, or I might of also sanded too much off the bamboo. I usually sand the bamboo after scrapping the rind because I always put a bunch of nicks on the bamboo with my scrapper no matter how careful I am it seems (very small but visible in the right reflective light). After the last one I have taken absolute care to scrape just the minimum to take the rind off, and only a couple swipes with a low grit sandpaper, like 400 or up. Anyway, I am about to make some bows around 100# and up, and I am wondering how each of these woods are gonna respond? Is maple known to be a good warbow backing?