Back set?

[Lil' Bow Pete]

weak back or weak belly?

[Bowjunkie]

Well, it's not quite that simple. To begin, 'back set' and 'set' are two different things.

Backset – The result (as effected by bowyer or nature) of setting the bow handle back toward the shooter and hence, the limb tips forward for greater efficiency.

Set - The result, usually due to belly compression/compaction, of a bow's inability to return to its original shape.

Is it 'set' that you're inquiring about?

There can be many other causes of set too. Moisture content, wood degredation, poor design, poor tillering, and plenty of other things.

Most all woods are stronger in tension resistance than compression, so if you're referring to a selfbow of a single piece of wood, chances are that part of the causes are ultimately related to the belly wood being overstrained, more-so than the back. But it could be a combination of both.

If you referring to a backed bow of some sort, you're going to have to be more specific.

[Lil' Bow Pete]

The bow is made of yew with laminated bamboo backing. My first experiment with the lam boo. It seems to be working but it has taken some set.  Not enough to wreck the bow but I have never seen yew take so much set.

[fujimo]

does it have a very radiused belly-
did you glue in amy backset

[Lil' Bow Pete]

the belly is flat with rounded edges
It was glued up straight with static curves 6"-8"long. The flpped tips compinsate for the set.