70 vs 80# limbs

TheCougar

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Joined
Jun 6, 2016
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Location
Virginia
I made the fatal mistake of shooting a Prime Centergy at my local bow shop. Now I’m angling to get one. My buddy who runs the shop recommended 80# limbs. I’m strongly considering it, because I have not problem drawing back the 70# limbs and I would be able to shoot a heavier arrow. I know I don’t NEED the extra KE and I and fully capable strength wise, so let’s table that discussion up front. I would probably back the limbs off to 74-75 lbs. My question: what are the speed benefits (70 vs 80 @ 29” draw and 425gr - at 70# my arrow is 292fps)? Guys talk about twisting the cables to get a few extra lbs out of 70# limbs - any drawback to this vs 80# limbs that are backed off? Will the limbs make the bow louder? Any other considerations? Thanks.
 

big44a4

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Joined
Jul 4, 2017
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597
My guess would be 3fps per lb. buddy got almost 30 by switching to 80# on his centergy. Bow isn’t any louder.


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AZElk

FNG
Joined
Jun 11, 2016
Messages
91
Location
Pheonix, Arizona
Me and all the technicians in the pro shop I work at shoot 80# centergy hybrids. You are gaining KE and will gain about 25 FPS for the extra 10 pounds of draw weight. I personally am shooting a 502 grain arrow at 80# and it is going out at 292. I have tested and backed the bow back down to 70 and I'm sitting right around 267 with the same arrow setup. I wouldn't recommend untwisting your main string to get a few extra pounds out of a 70 pound centergy due to that possible slight changes to your draw length and ATA. Prime's tend to run a little "hot" in the sense that they are always a few pounds over the intended max draw weight. If you are going to order a 80# bow it will probably weigh in maxed at around 82-83. The bow itself with 80 pound limbs is very quiet, the only dampeners I have put on it are stick on limb savers to the inside of the top and bottom limbs. The only other thing about noise it that we have noticed that the Pro-V rest is very loud on the Prime.
 

5MilesBack

"DADDY"
Joined
Feb 27, 2012
Messages
15,527
Location
Colorado Springs
I always wanted a bow with 80lb limbs just for the heck of it, but with a 32 1/2" draw I certainly wouldn't need that. Well, back in August right before hunting season my PSE Freak splintered a limb. PSE sent the only limbs they had available and the first thing I noticed was that they had a higher deflection number on them. After setting up the bow I shot it a few times through paper to get it close. I was thinking the new limbs were just stiff, but when put on the draw scale it was 80lbs.

Being a week before hunting season I wanted it set exactly as before for my sight, so kept turning it down until the chrono read 289fps, the speed I was shooting before the limb splintered. It shows 73lbs on the draw scale so that's probably what my bow was set at before with the 70lb limbs.

I want to turn the bow up now, but I use this bow for 3D as well and need to keep it within the speed limits. Also, even though the bow is now very well BH and bare shaft tuned, it isn't as consistent as it was before. When I change the strings out I might swap the limbs around a bit, or it may just prefer to be at max poundage........don't know yet. This is the first bow I've shot below max poundage.

So ya, you can turn the bow down but you may have to play around with it a bit to get it in the sweet spot.
 
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TheCougar

TheCougar

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Joined
Jun 6, 2016
Messages
3,070
Location
Virginia
Me and all the technicians in the pro shop I work at shoot 80# centergy hybrids. You are gaining KE and will gain about 25 FPS for the extra 10 pounds of draw weight. I personally am shooting a 502 grain arrow at 80# and it is going out at 292. I have tested and backed the bow back down to 70 and I'm sitting right around 267 with the same arrow setup. I wouldn't recommend untwisting your main string to get a few extra pounds out of a 70 pound centergy due to that possible slight changes to your draw length and ATA. Prime's tend to run a little "hot" in the sense that they are always a few pounds over the intended max draw weight. If you are going to order a 80# bow it will probably weigh in maxed at around 82-83. The bow itself with 80 pound limbs is very quiet, the only dampeners I have put on it are stick on limb savers to the inside of the top and bottom limbs. The only other thing about noise it that we have noticed that the Pro-V rest is very loud on the Prime.

Are you at Ross?
 
Joined
Apr 5, 2015
Messages
5,824
I am not a long time bow guy. On my second bow, a HOYT pro def 34 set at 75#. Fist bow was a HOYT turbo spider set at 65. I have a 30 inch draw. I use the same 438 grain arrow on both. Get 305 FPS from the 34 and 288 from the turbo. On flat ground in a good stance I can haul the 75 with no problem. Twice this season I have taken awkward shots. One kneeling and one twisted with my feet wonky because of the tree stand. I notice that extra poundage on less than perfect shots.
 

Dameon

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Joined
Mar 30, 2016
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438
Location
St. Louis, MO
Do it. I tuned my Hoyt Carbon Defiant Turbo to max at 75 lbs. I begged Hoyt for 80lb limbs, but no dice. If you have the strength, have good form, and practice as often as you can, I see no downsides so long as you’re not over bowed.


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noroads

FNG
Joined
Feb 24, 2012
Messages
66
Location
N.Idaho
I shoot a 80lb Centergy Hybrid and as others have mentioned it is not noticeably louder than 70# limbs, actually mine is really quiet with limbsavers and an aftermarket softer string stop. The draw is also very smooth and linear so 80# doesn’t feel much stiffer than 70#. I have 28” draw and only lost 9 fps when I went from 80 to 74lbs just to do some testing. As long as your maintain good form than go for the 80# limbs you can always shoot at lower poundage if you need.

My specs
28 1/8” DL @ 75% Let off
80#
554gr Axis 260 270fps
497gr Axis 300 284fps
 

Felix40

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Joined
Jul 27, 2015
Messages
1,874
Location
New Mexico
I have an older model elite gto with 80# limbs. I cant see any reason to drop weight any time soon. I borrowed a friends bow for a weekend and it felt like a toy at 65#. I dont know what kind of speed Im getting but if my pin gap got any tighter it would be impractical to have 10 yard increments. Im shooting a 530 grain arrow.
 

HookUp

WKR
Joined
Nov 4, 2015
Messages
957
I shot a deer last week with a bow tech prodigy at 72#. I'm headed to 80# next year looking hard at the Prime Centergy.
 
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