It's not exactly a straight, clean break, but it did break across the fibers. It amazed me how much weight that little strip of bamboo added--I noticed that when I unstrung the bow.
I am just amazed it didn't fret the belly.
When I made my IPE/Boo bow, I floor tillered the IPE blank, and it felt like 40lbs, threw the backing on, and went to like 80lbs.