I have made a couple of bows from large branches of sycamore; the kind of branches that shoot up when people "top" the trees. These were maybe 3-4" across, had some side to side waggle where the tiny side branches grew, and made cool looking bows with a few lumps and stuff on the backs. The wood was easy to cut, easy to work, and looked nice.
The bows shot fine with medium crowns, the wood was a lot like maple, but not as tension strong, I think. That's just my impression from a stick bending test. They were lightweight bows in the low 40 lbs range, and 66 or 68" long (don't remember), 2-2.25" wide, flatbows with flipped tips, I think. I tried a couple others at the same time, but I had a bad habit of coming in way low on weight back then, and I think I destroyed them messing with them, but I don't remember any breakage, just low weight pathetic set, giving up eventually.
I burn the stuff no problem in a fireplace. Oh, I know! The wood compares to yellow locust.