When is backing necessary?

[Pete W]

When is backing necessary on a board bow?
 Some places I read it is not necessary with a good board, other places say it is always needed.

 Is there a rule of thumb?
I am working on some Maple board bows and don't want to use backing unless I need to.  First it is hard to find backing wood, or bamboo, and I hate the look of most of the other options. I like wood.

I just made a 48" kid bow without any backing, it is 1 1/2" wide at the fade, pyramid limb to 1/2" at the tip.The limbs are just under 3/8". It draws to 24", but will be shot around 21".
 So far all seems well.
 I have a few more to build, as well as a couple for me.All are Maple, with no run outs on the side or back.

 Thanks

 Pete

[walkabout]

from what i know, backings are just insurance if the board is less than perfect. if you build pyramid bows and tiller correctly with a good board then its not really necessary. im not sure about maple but red oak for me is hard to find a good enough board to feel confident about not backing it.

[Eric Krewson]

I have given away a bunch of kids bows. I always back them with bamboo whether they need it or not. The reason is safety for the unknown legion of youngsters who might end up shooting them through the years. Good bamboo won't blow up like a solid piece of wood might.

[George Tsoukalas]

If the grain is straight tip to tip, you don't need a backing. If there are 2 run outs per limb then for a 50-55# bow  I don't back. If there are more than that I leave the bow i the stacks. If for peace of mind back it. Burlap, linen and silk are good. Gotta go. More on my site. Jawge
 http://georgeandjoni.home.comcast.net/~georgeandjoni/

[Silent Bear]

Anything under 50 inches I usually back with sinew, anything over isnt necessary if you have a good piece of wood with straight grain

[soopernate]

I am with Eric on this one.  I too always back kids bows with bamboo just because kids are rough on things and all it takes is getting dropped once and a bow could blow.  Other than that I use fiberglass for its ruggedness.