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Main Boards => The Bowyer's Bench => Topic started by: rockkiller on February 08, 2016, 03:35:00 PM
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I think I asked this question before and have done a search and cant find it.This getting senile is getting old :knothead:
I am building a glass bow for my grandson and it came in pretty heavy.So here is my question...which side of limb to trap to lose weight ,or does it make a difference ?
Thanks for any help.
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The back. If its real heavy, you could narrow the limbs a tad.
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Back is prefered. On longbows I have trapped the belly and it worked well, just liked,the look better.
It has been written some where that removing the width on the back adjusting tension strength is prefered over reducing the compression on the belly side.
If your limbs are plenty wide then like Roy said taking some off each edge work well.
Just trapping could result in 3 to 5 pounds, this was on a 60 plus pound long bow though.
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Thanks for your help. :notworthy:
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I'm no expert, but I think if you need to reduce weight significantly, you'll lose more weight by trapping the belly. I spoke with Steve Turay (Northern Mist Longbows) a couple of years about this. According to Steve, the fiberglass provides more stiffness (resistance to bending of the limbs; draw weight) in compression (belly) than in tension (back). So Steve traps the back on his longbows because his thinking is that if he narrows (traps) the back by a given amount, the bow will retain more draw weight than if he were to narrow (trap) the belly by the exact same amount instead. So, either way he would be removing the same amount of material (mass, weight) from the limbs, but by trapping the back the bow will end up with a higher draw weight than if he trapped the belly. Lighter limbs for a given draw weight is his preference-- squeezes a little extra performance out of the bow. So, his experience has been that he'll lose less draw weight by trapping the back instead of the belly.
Macbow says above "It has been written somewhere that removing the width on the back adjusting tension strength is prefered over reducing the compression on the belly side." This may be for the same reason that Steve does his bows this way-- to maximize performance, not to maximize the reduction in draw weight.
But I'm guessing the difference in performance isn't all that much. It sounds like you need to get a significant draw weight reduction, so I think you'll get more weight reduction by trapping the belly than the back. Or as Roy says above, you could narrow the limbs. If you really need to drop weight, you could narrow the limbs and also trap the belly (depending on the current limb width).
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Typo above-- meant to say "I spoke with Steve Turay a couple of years ago about this".
I don't think Steve would have wanted to talk to me for a couple of years about this-- he's a nice guy, but no one's got that much patience.
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How much weight do you want to lose and is it a recurve or a longbow eg. what thickness are the limbs?
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Originally posted by mikkekeswick:
How much weight do you want to lose and is it a recurve or a longbow eg. what thickness are the limbs?
It is a glass longbow .I was going for 22# or 23# @ 22 with a stack of .250. It came out to 28 lbs.I have got it down to 25lbs by narrowing the limbs and sanding.
I may just call it good.