wood-backed d/r bows tillering and thickness

[Badger]

   I routinely used to put my tips between 4 1/2 to 5" behind the back of the bow. Now I normally go about 3 1/2.

[upstatenybowyer]

Here's a pic of the old caul I was using and the new one I'm making after starting this thread. I really tried to make the curves more gradual and the reflex less dramatic.

[Badger]

That first caul doesn't really look too bad, I would have extended the straight part of the limb maybe a couple of inches more.

[Bayou Ben]

Yeah, I think you can pull off that 1st one if you follow the steps you mentioned.  Having an idea about final thickness of your bow will help too.  It's hard to maintain even taper when you have to remove a lot of wood from a curvy r/d bow.

[upstatenybowyer]

Interesting. I've gotten pretty good at estimating my final thickness taper prior to tillering when I'm building a self-bow, but I feel like it's a whole other ballgame when making one of these wood-backed numbers.

Is that true?

In other words, do you need less thickness with a wood-backed bow because the back is completely flat and thus tension is perfectly distributed across the surface?

[DC]

I think it is but not a lot thinner. I just looked a some of my bows and the backed ones may be 1/32" thinner, maybe a bit more. It's hard to say because some are wider than others and that skews the look.

[Bayou Ben]

Yeah I think you'll have a little less combined thickness than a stave by itself, but I don't think it has to do with the back being flat.  A lot of guys that I've seen taper their backs, including me.  It's the overall taper that gives you the bend; not where the taper is located assuming your back and core are similar strength woods.
 
 

[Bayou Ben]

Just realized what you meant by the back completely flat comment; yeah that seems logical.  I never really thought about it as most of the bows I've worked with recently have been backed.