There are a wide variety of belly options depending on what exactly your looking to get out of the bow. Osage is always a spectacular belly wood, it will make anything you want and seems to be consistently “good” for lack of a better work.
One of my favorite belly woods is black locust. It grows straighter than Osage which makes finding good grain pretty easy. BL is lighter then Osage, but with a good heat treatment it becomes very stiff and springy, similar to Osage. Osage is a more elastic wood, but black locust is really hard to beat for an all around good wood. I have had some black locust that was lackluster, but most often it is good. I’ve backed BL with bamboo and maple, I believe that maple is a better choice of the two but both work very well.
There are MANY belly woods that I have yet to try out. Two of them on my short list are maple backed black walnut and maple backed cherry. I believe both will make lightweight sweet shooting bows. Heat treated white woods also make for good belly woods. Hickory, ash, birch, hop hornbeam,hackberry and hard maple all come to mind.
The cores in my tri-lams are always hard maple. Maple is strong and lightweight, proving to be the perfect qualities for a good core wood.
Laminated bows are a lot of fun from the almost endless combinations that can be made. They are completely different then building selfbows, but both are great in their own way.
Cheers,
Taylor