Over-drawing a BBI bow??

[arachnid]

Hi guys.
Just a question- I have a 45# BBI that I love to shoot. I want to let a guy try it out for a few shots, but the bow is tillered to my draw length which is 26" and his draw length is 29.5".
I know it's not recommended to over draw a wooden bow but will a few over-drawn shots ruin or might break it? It's BBI afrer all, that stuff is HARD...

[ajooter]

I wouldnt let anybody draw a bow 3+ inches past its intended draw length without testing it first.  Personally a bow tillered to 26" shouldnt ever be drawn that far unless it is extremely overbuilt.

[Pat B]

If a bow is tillered for 26" than it's max draw length is 26".

[Badger]

  One overdraw can kill the performance of a bow.

[cool_98_555]

+1 for Pat, aj, and badger.  Let me tell you something from experience with this topic.  I once made a bow for a guy I worked with, who claimed he had shot traditional bows before and wanted to pay me to make him one, so I agreed.  He told me his draw length was 28".  I made him a bamboo-backed hickory with an arrow shelf, around 65" long, tiller was spot-on.  I shot the bow around 100 times.  When I brought it to him to try it out to see if the draw weight was what he wanted before I finished out the bow, he pointed the bow in the air, drew the bow all the way back to the back of his ear, and **snap**.  The distance from the corner of his mouth to the back of his ear was at least 3 inches, maybe 4.  Hickory can take a lot of punishment, and at 65" you'd think that it would be fine, but I tillered that thing out to 28", and being taken out to 30 or 31" broke the bow.  Unless you have a 26"-27" arrow for that bow, I wouldn't let anyone else with a longer draw length shoot it.  You could let them, but only allow them to use the 26"-27" arrows in the bow.  If that hadn't broke, I can guarantee you that an overdraw like that would have caused a lot of set afterwards.

[Del the cat]

Why would you even think of it? Unless he wants to pay for it and keep it...
Even if it doesn't explode it will spoil it's performance at 26".
Del

[arachnid]

OK.... didn`t though of that.... But then again, I never let other people shoot the bows I use, only the "expendable" bows...
Thanks guys.

[DC]

I hope this isn't hijacking but what does "tillered at 26" mean? Lets say I have a bow that I worked until it was 38#@26". What is the difference between that and a bow that pulls 40#@27". Why, if I stopped tillering at 26" would it break at 27". I've often wondered when I start on a bow and the bend looks really nice with 40# at 15" why I can't just pull it and have one of those 100# bows. Who's to say when it's going to break? Just because I chose to stop tillering doesn't mean the bow won't bend some more.

[mikekeswick]

I hope this isn't hijacking but what does "tillered at 26" mean? Lets say I have a bow that I worked until it was 38#@26". What is the difference between that and a bow that pulls 40#@27". Why, if I stopped tillering at 26" would it break at 27". I've often wondered when I start on a bow and the bend looks really nice with 40# at 15" why I can't just pull it and have one of those 100# bows. Who's to say when it's going to break? Just because I chose to stop tillering doesn't mean the bow won't bend some more.

Maybe...maybe not...
The reason is that whilst it may not show any weak spots at 26 it may well at 27, 28 that is the whole idea of tillering. Once a bow is shot in at a certain drawlength then the wood gets used to being drawn to that length.
If you want to make a 100# bow then you should do the same as any weight bow during tillering - always pull it to the desired weight unless you see a weak spot on the way to that weight. Making good bows is about reading the wood as you progress through tillering, reading those intial slight indications of set, where they are on the limbs, is the distribution of set concurant with the limb width profile etc...How does the set increase compared to how far you are pulling it. Too much set early on then your wood needs to be thinner for the bend you are asking from it. tillering is really learning how to read what the wood is telling you. Tillering to 15 then just pulling it to full draw means you have no control over all these things and you'd better have one hell of an 'eye'!

[Badger]

  I draw a bow just a tad over 26". I usually tiller my bows out to 28". I can't tell you hom many times I have regretted doing that because the extra 2" cost me performance. I feel better with a little safety margin but it can cost you.

[Pat B]

"A bow fully drawn is 9/10th broken!"

[DC]

Thank guys. I've always thought that once I got it bending evenly that after that I was just evenly removing wood until I got to draw weight. Most of the time that seems to work. If the tiller did change I assumed that I had screwed up. It never occurred to me that the wood had changed. I'll keep my eyes on that.

[bradsmith2010]

good advice above,, if you want to let him shoot it,, make a 26 inch arrow and let him shoot that,, he can get the feel for the bow but won't overdraw it,, ok 25 1/2 inch arrow just in case,,

[mullet]

Also not mentioned, Bamboo backed ipe has a tendency to chrysal when over stressed. I know, I've pulled a few too far.