Is there any real reason to sinew back osage?

[loefflerchuck]

I grew up in Colorado and have lived in California and now Utah. For the last 25 years I have backed 95% of the bows I have made with sinew. Probably close to 1000 by now.  Last year was the first time I used osage. My first bow was 44" long. I gave it a big reflex. At full draw of 22" it still maintained a double curve and weighed 65#. It was then that I realized all the hype of osage was real. I also wondered why anyone would spend the time and add the weight of sinew to this perfect wood?  Unless of corse you wanted to add draw weight or fix a mistake or flaw. So my question is......-- Can someone give me a real reason to back a perfectly made osage bow with sinew? Can it handle a huge amount of compression without the belly starting to fail and the bow declining in performance?   I am a new guy to osage. I want to know what people think. I also ask because I am making a 53" n t n 5 curve bow for someone who thought they had a 26" draw but it turned out it's 28". It's a narrow southern plains style 1 1/8 wide at the handle tapering to 1/2 below the nock. It only has one small knot mid limb and will only be 45# at 28". The reflex at the handle will decrease at full draw for a semi bendy handle. If this bow is made right will this be a case where sinew will actually improve osage?
Thanks for your opinions.
Chuck 

[JonW]

Chuck I haven't come close to the amount of bows made to you. But I think you have a prime candidate for sinew backing. It will give you the amount of draw you are needing in this case. I like to sinew back Osage because it will allow you to "overdraw" the bow without getting a lot of set and set as we know comes with a loss in performance. Normally Osage doesn't need sinew but sometimes it does.

[loefflerchuck]

Thanks Jon. Thats the kind of answer I am looking for.

[Joec123able]

I think most people use sinew on Osage for high stressed designs. Osage has incredible compression strenth but it's not invincible it can chrysal or fret just like any other wood When pushed far enough keep that in mind

[mikekeswick]

The things to bear in mind are sinews properties.
High density when mixed in the glue matrix of 1.3 s.g.
Low stretch resistance - less than wood. So it's not offering as much 'extra' draw weight over wood at the same thickness and it's way heavier than most woods.
It can stratch upto 8% of its length. Wood 1%......so you will never break a (well done) sinew backing even if the wood looks like it's hinging! Or the other way is to think - a wood bow needs to be bent to close on it's limits to perform well however you are never, never going to get sinew working hard on a wood bellied bow.
So when you think about all this you come up with the question 'why even bother?' Like you have done.
Sinew simply lets you make shorter wooden bows than if they were unbacked. Just like Joec123 said tension strength is the problem that will break a bow and sinew elliminates this potential problem.
As sinew has lower bend resistance than wood it also moves the neutral plane when compared to an 'all things equal' wooden bow and helps with compression forces a little. 

[burn em up chuck]

   Ive heard but can't substantiate that sinew can increase arrow speed as much as 20 percent.

                                                                           just sayen chuck

[Pappy]

Can't really get into the technical stuff like a lot of these folks can ,but the only reason I sinew back Osage is just what you have,short bow that I want a longer draw length than I would nominally deem safe.  Looks like you have a good candidate. 
   Pappy

[mikekeswick]

   Ive heard but can't substantiate that sinew can increase arrow speed as much as 20 percent.

                                                                           just sayen chuck

I've heard we went to the moon as well.......

[paulsemp]

1000 bows and never worked with Osage!  I am sorry

[adb]

1000 bows, wow. What do you do with them all?

[PEARL DRUMS]

That's only 4 a month for 25 years straight......lazy.....

[paulsemp]

and 950 of them are back with sinew!

[loefflerchuck]

Thanks everyone. Joe, thats what I thought. Mike- I'm working on my 12th hornbow and see just what sinew can do. My main thing is getting the best glue and making sure everything with the glue is done right.  My favorite woods even after osage are still incense cedar, juniper and yew. The first two with sinew backing of course. I think in those two woods it will increase arrow speed a bit and keep them from exploding after 100 shots or so.
 Everyone else---- The 1000 bow thing I pulled out of the air last night writing this thinking mainly the last few years. It was a accidental lie. After putting thought into it the real number is probably a little over 400 and most are being used by someone somewhere. I still do have way too many here though. Sorry about that tall tale. I have had a life after all. And yes they are almost all backed with sinew.

[blackhawk]

I still do have way too many here though. And yes they are almost all backed with sinew.

I can help you with that problem and I'll take a couple off your hands...I'd take a couple of your bows...you make cool sinewed bows

[PEARL DRUMS]

400 or 1000, its still a huge bunch of bows Chuck.