Ok.. I've never made a bow from Sycamore (acer psudoplatanus), but I have made atlatl's and sculptures from this tree, and it's nice wood
Remember that it's a member of the Maple family of trees ( Acer)
Its very common in the UK although not native to our shores
I plan on making a bow from a stave I have very soon, I'm just going to keep it long and wide.
I imagine a pristine quarter sawn length board would make a fine core for a laminate ?
Good luck