actually you can leave every wood unbacked, as long as you treat it well. Some woods are worse in tension than others, the tension strong ones take bare backs way better as tension weak woods, or are even used as backings.
Sycamoore is callled tension strong, wich means it does very well unbacked, and it's used to back lighter, tension weak woods, like Black Cherry. According to many bowyers Sycamore is a great bowwood, and it happens I just found a nice bunch of it, exactly today! I've been searching for it quite a while. So my first sycamoore staves will come soon!
if you're a beginning bowyer, 66"nock to nock would be a good length, but 68 is safer. If your first or second bow, I'd go for 72", 8" handle area, 2" at fades, tapering from midlimb to 1/2" nocks. With some skill you can make it 64" or smaller, 65-68 is considered as ideal for 28" drawlength. But as I said, it's better for beginners to make them some inches longer
Nick
