So, the glue line will change the hysteresis of the wood? How? The gluing happens at the molecular level. A good glue line really isn't a line at all. Just because two different woods are glued together, doesn't mean the hysteresis of each type of wood will magically change. The entire hysteresis of the total limb may change depending on the combination of woods used. Sounds to me like you're guessing.
Yes, it doesn't take much ipe to make a bow. But, we were talking flatbows here (I was, anyway) when I offered dimensions. One of my bread & butter bows is a backed ipe flatbow. I easily make more backed ipe flatbows than any other type (and recurves, as well). It just works out for me... easy access to good quality reasonably priced ipe is a no-brainer.
66" ntn for longer draws and heavier weights, and down to 60" ntn for shorter draws and lighter weights. I make them all with an 8" long handle/riser with multilams to a total thickness in the grip of 1.25". They're pyramid bows, 1.5" wide at the fades, tapering to 1/2" or 3/8" tips. For bows up to 50#, I use 3/8" thick belly lam slats, with a 3/16" backing. Above 50#, I go with 1/2" thick belly slats and 1/4" backing. I've made bows with this design from 25#-75# with no failures. Dead simple, foolproof design and material.
For ELBs, even warbows >100#, I would never go more than 1.25" at the handle with ipe.
