I am currently planning out a bow right now (sinew-backed Juniper) that is going to have a set-back handle area, as well as some slight recurve on the tips. I have been reading as much as I can about similar bows, but I have come to a bit of a problem.  I have seen some information regarding the belly x-section that has been contradictory, i.e. flat vs. round. The only bow I have seen that was similar in materials and shape (SB'ed Juniper with recurve) had a round belly (to help prevent splintering, chrysalling, etc). But I was just reading vol. 3 of TTB, and Jim Hamm stated that bows with this kind of curvature require a flat belly (to handle the compression). Does anyone here have any idea about the route I should take? Unfortunately, I really can't experiment with the two designs (lack of resources and time). Any help would be appreciated.

A well-built round belly bow may compress more and follow the string a bit more but will have less mass at the tips so it will still be an efficient bow.

A flat belly bow may follow the string less and can be very efficient but it loses something in the aesthetic.

In the end, you can make a beautiful, great shooting bow either way.  But don't expect your first one of any style to be great.  You will have to put resources into it to have a good result.  In other words, your first or fifth or tenth may not meet your expectations no matter what style you choose.

I recently finished a sinew backed erc.  I went with a rounded belly.  I had read that the compression of erc was good and could handle the rounded belly. It turned out to be a really nice shooting bow.  I can send you pics if you want.

QuoteOriginally posted by mwosborn:
I recently finished a sinew backed erc.  I went with a rounded belly.  I had read that the compression of erc was good and could handle the rounded belly. It turned out to be a really nice shooting bow.  I can send you pics if you want.

Please do. Did you put any curves in your bow? And how much heartwood did you manage to get in the belly?

I make all of my bows with a rounded belly. Flat flatbows just ain't done yet  

can you post pics of the erc?

Here are a couple pics - thought I posted some here a while back, but can't find the post!

UN - I did not put any curves in it.  The sinew has kept it dead straight with no set.  Been shooting it for a couple of months now.  I really like the way it shoots and will definitely make some more from erc!  I am sure you could curve the tips some - although I have never tried to bend erc.  I did not use heat on this one at all as the stave it came from was nice and straight.


IMG_1963  by  mwosborn1 , on Flickr


IMG_1964  by  mwosborn1 , on Flickr


IMG_1962  by  mwosborn1 , on Flickr


IMG_1961  by  mwosborn1 , on Flickr

mwosborn, that's nice. What are the specs on her? Length, width, draw weight, etc?

That big knot in the last pic doesn't affect the bow at all?

Beautiful bow    

the post of the ERC by thenatural.....


http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=009755;p=1#000000

I keep low compression woods flat with slightly rounded edges and high compression woods getting rounded off. The highest point does the most work, it only makes sense to me.

The knot doesn't seem to bother anything.  I just followed the grain around it.  This was about as knot free erc that I could find.  

Looks like Igor found the other post - it has the specs if your interested.

Very nice bow.

Thanks Roy - slowly learning!  

Very nice ERC. I like th elook of mixed sapwod and heartwood. I will have to try one like that with nearly all sapwood.

Regarding the flat belly vs round, I agree it's not that big of a deal, obviously the absolute most efficient design is a flat belly, with that said, if you prefer the look of a rounded belly, I say go for it. No one shoots trad bows for the smoking unbeliuevable speed and performance ... what is a couple FPS really.

I keep all mine for the most part flat for two reasons, one I think it's harder to get a perfectly even and smooth looking round belly, I like the mix of old and new you get with a wood bow having a flat profile like the fancy factory bows.

Yeah, that's a great looking bow! Thank you for the pics, hope mine turns out half as nice. Well, I guess I can at least hope mine doesn't snap in half from the strain of the design.

Use to make round belly bows but like John I found the limbs took on more set than I liked. Lately I make flat belly bows that slowly transition into a round profile towards the tips starting somewhere in the midlimb.  That being said ERC looks really nice with a round belly.  Highlights the wood more.

I agree with what Pearlie said. radiused belly for compression strong woods and flat belly for everything else.
Very nice looking bow, mwosborn. Sinew backed ERC is on my list.