Hi, I built one bamboo backed ash bow several years ago. I used 1 3/4 in wide lumber yard ash and strips from a narrow bamboo pole. I split the pole and flattened each strip, then laid them parallel as baking. The strips were quite thin, ( almost like strips from a window blind.) I got a shootable bow ~ 40# but ~ 1 3/4 inches of string follow. My feeling has always been that even that thin bamboo backing over powered the ash. Of course it could be that I'm just not talented a bowyer. Ron