Working out spine weight

[JW_Halverson]

Anyone knows me knows I would rather eat broken glass than make arrows. Maybe because of this my brain refuses to have any confidence with trying to figure out what spine weight arrows I should start with when making them for a bow.

So, I have a bow that came in at 59# at 28" measured from the bottom of the arrow nock to the back of the bow. No arrow cut in shelf (*spits on ground*). I wanted to make 29" arrows to go with the bow, so I would go with 65/70# spine, right?

If they act a little weak, I have a bit I can trim them down to stiffen up, no?

[paulsemp]

55# with 125 head is where I'd start. Make,buy or trade for a spine tester and find a good shooter and try to repeat what is shooting well. I wasted so much time before guessing. Yes trimming or lighter point makes heavier spine. Can also sand shafts to be the same. No two people shoot the same way, so not one size fits all even more so off hand in my opinion. Not having center or close to center shot is always a deduction in spine. Plus most self bow guy have a real problem consistently hitting the same draw so spine is all over as draw length is changing. Most guys need to develop a good draw cycle before locking in a spine. Sorry for the rant but I used to hate making arrows before also. Now I love making them and knowing they will fly right instead of guessing.

[Pappy]

First off are you drawing it 28 ? if so since it is not cut in I would start with 30 inch shafts 50-55 if weak just trim 1/4 at a time to get it where you want it, if not adjust according to the weight you really draw .I usually wind up 5 to 10 under what the draw weight is on self bows that are not cut back to close to center which I never do on mine, lots of people do now days and you can shoot a stiffer arrow when cut to center or close. when you order arrows remember the spline you order are figured for a 28 inch arrow with 125 tip, for every inch longer than 28 spline goes down by about 5 lbs for every inch shorter that 28 it goes up about 5lbs, adding more tip weight reduces the spline and reducing the tip weight increases the spline just not as much, maybe a couple of lbs. per. 25 grains.  Also be sure to put the stiff side of the arrow toward the riser.  Sorry for the long post, much easier to show somebody that to try and tell them in type. 
 Pappy

[JW_Halverson]

First off are you drawing it 28 ? if so since it is not cut in I would start with 30 inch shafts 50-55 if weak just trim 1/4 at a time to get it where you want it, if not adjust according to the weight you really draw .I usually wind up 5 to 10 under what the draw weight is on self bows that are not cut back to close to center which I never do on mine, lots of people do now days and you can shoot a stiffer arrow when cut to center or close. when you order arrows remember the spline you order are figured for a 28 inch arrow with 125 tip, for every inch longer than 28 spline goes down by about 5 lbs for every inch shorter that 28 it goes up about 5lbs, adding more tip weight reduces the spline and reducing the tip weight increases the spline just not as much, maybe a couple of lbs. per. 25 grains.  Also be sure to put the stiff side of the arrow toward the riser.  Sorry for the long post, much easier to show somebody that to try and tell them in type. 
 Pappy

I shoot a locked in 26" draw. My form is pretty solid. But this bow isn't for me and the guy seems pretty sure his draw is 28".  I have no way to measure his draw and I'm not able to take him to a range and shoot arrows to see how they fly. I just gotta make my best guess and then leave the fletching large to correct as best it can!

[Pappy]

Then if I was making a guess I would go with 45/50 cut at 29, I bet they will fly. 
 Pappy