Author Topic: Approximately how much weight will I gain...  (Read 1847 times)

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Offline ssrhythm

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Approximately how much weight will I gain...
« on: February 13, 2023, 04:52:28 pm »
What poundage gain can you expect per inch of bow length reduction?  I can not find my TBB with that info in it...my house is a wreck and in need of a major spring cleaning!

Offline Deerhunter21

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Re: Approximately how much weight will I gain...
« Reply #1 on: February 13, 2023, 07:07:35 pm »
ohhhh... i cant remember for sure... but I believe for every inch you pike, it gains 5#. Just make sure you don't lose the 5# retillering! that's what happened to me  ;)
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Offline bradsmith2010

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Re: Approximately how much weight will I gain...
« Reply #2 on: February 13, 2023, 08:02:01 pm »
you can tie a nock where you gonna pike and see,,

Offline PEARL DRUMS

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Re: Approximately how much weight will I gain...
« Reply #3 on: February 14, 2023, 12:40:15 pm »
Very little on most bows. 1-3# per inch per limb. Generally you have to scratch a bit on the limb you shortened to get the tiller back in tune, that takes away a majority of your gain.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline George Tsoukalas

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Re: Approximately how much weight will I gain...
« Reply #4 on: February 14, 2023, 02:06:13 pm »
About 5# which may be offset by more set. Jawge
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Offline ssrhythm

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Re: Approximately how much weight will I gain...
« Reply #5 on: February 14, 2023, 05:27:55 pm »
Thanks for the replies.  See my "redoing my trade bow" thread above to understand why I asked this question in the first place.

Offline Selfbowman

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Re: Approximately how much weight will I gain...
« Reply #6 on: February 14, 2023, 05:35:10 pm »
What Pearl said
Well I'll say!!  Osage is king!!

Offline bradsmith2010

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Re: Approximately how much weight will I gain...
« Reply #7 on: February 14, 2023, 06:27:06 pm »
   well ok, its not always a wash,, if the bow is too long,,and mass weight is too much,, making it shorter can raise the  draw weight and also make it more effecient,, dont make me go back and post notes ,, from chronograph testing,, I have had  good results and not so good results,,so it depends on the starting point,,
   

Offline bradsmith2010

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Re: Approximately how much weight will I gain...
« Reply #8 on: February 14, 2023, 06:52:49 pm »
well ok I found my notes not as exact as I like but from 1997,,,was using chrono then,,
  then main flaw, i didnt note how long the bow was,,
  it was 50# at 27  and shooting a 424 grain arrow 154fps, im sure it was a heavy b5o string,,
  I cut the bow to 67 inches and it was 61#@ 27 inches,,
  it would shoot the same arrow 176 fps,,
  Im pretty sure the bow was 70 inches or so and had horn nocks,, so not only did I increase draw weight but reduced mass the tips as well,,
  I dont have notes on the failures,, (-S

Offline Selfbowman

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Re: Approximately how much weight will I gain...
« Reply #9 on: February 14, 2023, 07:58:34 pm »
well ok I found my notes not as exact as I like but from 1997,,,was using chrono then,,
  then main flaw, i didnt note how long the bow was,,
  it was 50# at 27  and shooting a 424 grain arrow 154fps, im sure it was a heavy b5o string,,
  I cut the bow to 67 inches and it was 61#@ 27 inches,,
  it would shoot the same arrow 176 fps,,
  Im pretty sure the bow was 70 inches or so and had horn nocks,, so not only did I increase draw weight but reduced mass the tips as well,,
  I dont have notes on the failures,, (-S

Yes Brad I try to forget the failures after I learn my lesson.🤠
Well I'll say!!  Osage is king!!

Offline George Tsoukalas

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Re: Approximately how much weight will I gain...
« Reply #10 on: February 14, 2023, 11:27:05 pm »
Jim Hamm, of eternal memory, gave a formula in TBB 1.
If I remember correctly, it worked out to about 5# provided 1 inch is taken off each limb. He accounted for several factors.

It's too late for me to go searching. By now most bowyers have TBB 1 anyway.
Jawge

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If you ain't breakin' you ain't makin!

Offline ssrhythm

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Re: Approximately how much weight will I gain...
« Reply #11 on: February 15, 2023, 01:01:24 am »
The bow was definitely too long and was well below max efficiency.  I started making it for a very tall friend of mine and figured a longer bow would work out for him.  It turned into my trade bow when my trade bow popped and time became an issue.  I turned it into a pretty nice shooting selfbow that was very easy to shoot very accurately.  It had a tough more hand shock that I was happy with, but it was a shooter.  It started ticking the last session of shooting and arrow tuning I did before I was going to ship it. 

It was 59# @28” and 67” tip to tip.  My plan is to chase the next growth ring removing the compromised back.  I’m hoping the weight reduction there will be a wash with improved efficiency and increased draw weight once I remove 2.5-3 inches from each tip, recurve the bow, and sinew back it. 

If I end up with a 48# @ 28” or higher 62” sinew backed recurve, I’ll be very happy.  I don’t know how much taking it down to the next ring is going to drop the draw weight, but if I gain ~ 15 lbs by taking off 3” per limb and a few pounds with a greater degree of recurve and a few lbs by the reflex the sinew should induce, I think it could work out……if I get really lucky.


Offline Pappy

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Re: Approximately how much weight will I gain...
« Reply #12 on: February 15, 2023, 08:09:50 am »
I have had good luck over the years piking them, usually about 3 lbs per inch and if the tiller was good to start with it usually don't change it much, don't do it as much as I use to, gotten better at hitting weight but it has always been an option if the bow was long enough to accommodate the draw length I wanted.  :) very minimum for me is double the draw length i want and add in non moving part/handle and fads.
 Pappy
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Offline George Tsoukalas

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Re: Approximately how much weight will I gain...
« Reply #13 on: February 15, 2023, 10:10:19 am »
TBB 1 P. 283
Basically, 3/4" from each tip will raise the weight from 52# to 58#.
Jawge
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If you ain't breakin' you ain't makin!

Offline bradsmith2010

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Re: Approximately how much weight will I gain...
« Reply #14 on: February 15, 2023, 12:33:06 pm »
can u just sinew over the back as is,, more details and pics please