Reducing Poundage on a Laminated Bow

[Antonio]

I have a spare 80lbs longbow and what I want to do is reduce the Poundage down to 55 to 60 and give it to a relative .
any ideas on how I can do that .the emphasis is on the (CAN) do .
If a man can walk on the Moon and Build Piramids surely some people around here can help me reduce a 80Lbs Laminated longbow to 55 to 60 LBS.
and save me some money in the Process.

[otis.drum]

probably should talk to longbow steve, greay beard, grahameA or someone like that.

i have done it but am no expert. your bows limb design may not like it either. i would suggest that a limb thin in its depth, but wide in its width will handle it better than the opposite.

it's not as simple as just go and take this much off. you need to take some off and check and retiller. take some more etc etc. you need to keep an eye on the limbs, where they are bending, where they are stressed and might fail.

you could take some off the sides sqaure to the back and belly, or trapezoid the sides towards the belly, or sand the glass back.

bows are not that dear to buy new. you can pick them up for a couple of hundred bucks. perhaps a better option? JMO

[Stickbow Hunter]

Antonio,

I agree with Otis. I honestly think you are better off leaving the bow alone as 20 - 25 pound is too much to try and reduce the weight by.

Jeff

[Antonio]

Thank you Otis and thank you Jeff. it sounds a little complicated and difficult to get right.I thought about rounding the front of the Bow the part that faces me Like you mentioned Otis .but then I thought if it needs to much rounding its going to look like the glass will be to thin.I have not made any Bows and you Both have .

so I assume that more than once you might just by chance gotten the weight wrong on the bow and you might have tried this some how before .

I might get one of those Ausbow Industries Longbow Kit and have a go .see How that goes .Hopefully Good.

thanks for the feed back.

the Bow shoots good so I wont tamper with it .
If it ain't broke don't fix it just make an other one .will have to be the motto for this one.

[Stephen Georgiou]

hello there antonio,
I have taken the weight off 2 bows.
One was an internature 55lb back to 42 lb
the other was my pride and joy. It was 73lb @28" I wanted to take it back to 50lb but that was too much. I ended up with 55lb @28" this bow shoots as well now as it did at the heavier weight.

What I did to take to weight off was to cover the front face with masking tape and draw a line down the center of the bow. I then marked off the limbs at one inch intervals from the tips of the limbs to the center of the grip. Luckily the limbs where already prefect in length so I was then able to draw 2 lines on each limb from the nock point to the fade out. this gave me tapered lines that i then check against my marks to see that everything was equal. I then sanded the edges of the limbs down to his line. this made the limbs narrower. this removed poundage without effecting the tiller of the bow. I then recut the shelf to 1/8" off center shot. Once I got the limbs where they looked right I put it on a tillering board and gave the bow a 3/16" tiller/bottom limb heavy.

This bow is still my favorite bow to shoot and performs very nicely.

It is your choice but if you are very good with timber work then it is worth a try because it is very rewarding if you get it right. Nealy as good as making a bow from scratch.

Cheers. SG

[otis.drum]

this removed poundage without effecting the tiller of the bow.

stephen, this may have worked for you but there are too many variables to say this will work with all bows.

limb thickness
limb width
glass/wood ration
limb shape
degree of taper you remove
width of tips when done
pressure on fades when done

if the tiller is effected, retillering can be an art in itself.

i have sucessfully reduced bows too, but its not as easy as 'taking a bit off each side'. especially if someone hasn't had much bow fiddling experience.

antonio,
building bows is great, and i absolutely love it. but to buy a kit and the tools required to do the job will likely end up dearer than buying a bow. so unless you're looking to keep building bows, then i rekon, safe be is to just buy one. again JMO

[Stephen Georgiou]

You are right otis. this bow was well built in the first place.

Even though it worked ok I still fine tuned it on the tillering board.

The best way to learn is to have a go i suppose.

I did a hell of a lot of reading and went through the build alongs and watch youtube videos before I tackled if though.
SG

[otis.drum]

yeah no worries SG, i wasn't challenging you. just suggesting it's not the best option for everyone and every bow.

i have reduced bow draw weights by between 15-35#, the later being a lot, but came off a 105# bow that was good to no one that i knew, so had to be done. the fades are one place to be careful of. they're one place you don't want too much added stress. i have begun to thin less around the fades when reducing now. i like to taper my thinning from behind the fades but only slowly until a bit past the fades, and strongest about 2-3" past the fades, and then taper slowly back along the rest on the limb towards the tip. i have found trapping to work pretty well like this, and have a couple of good shooters i have trapped down in weight. it's important not to thin the tips too much though as they get the urge to twist when stringing if too thin i have found.

[Steven J]

Antonio,

My simple answer would be to say that you can't do it and maintain the integrity of the bow. You can drop some weight from the designed weight but your target of 25% is pretty large.

Your emphasis is on the can do so here are some more constructive ideas.

Take thickness from the glass by careful sanding. I have done this on a bow that was 70lb and took it down to about 55lb. Sand evenly on both limbs by counting strokes and you will drop the weight. Taking thickness has more effect than taking width.

The alternative is taking width. I would taper the limb more strongly. If the nock is currently 12mm take it down to 10mm and see what happens.

There is no formula that I can give you of the top of my head to help with figuring how much to take.

Steve

[ichiban]

hmm i wouldnt try it personaly.... unless you hate the bow? if its a long bow (i.e no recurve, no deflex no reflex) then it might be possable but still a very scary thought.... all i can think is twice the width = twice as strong if it was going to be done that would be the way but everything would have to be 100%