Changed out my limbs now bow seems to be quite jumpy?

[Mike_W]

I recently had a shop change out my limbs for me on my Athens accomplice 34.
This is a draw length specific bianary cam bow that uses adjustable draw stops.

Both cams are set the same and in time but when I anchor the bow just seems much more"jumpy" than it was.

Any ideas why?

[L.O.S.T.Arrow]

Mike...Most likely your draw has changed slightly shorter or even longer...

Adjust the draw stops either way until it feels Familiar or comforatable again...

1/8 adjstment on my draw stops goes from perfect to very jumpy like it wants to take off on its own...

Any creeping of the draw will set off this action...making you pull hard into the wall...straining muscles and bow feels uncomfortable

make sure draw stops are in sync for that draw setting...

Neil

[Mike_W]

Originally Posted by L.O.S.T.Arrow

Mike...Most likely your draw has changed slightly shorter or even longer...

Adjust the draw stops either way until it feels Familiar or comforatable again...

1/8 adjstment on my draw stops goes from perfect to very jumpy like it wants to take off on its own...

Any creeping of the draw will set off this action...making you pull hard into the wall...straining muscles and bow feels uncomfortable

make sure draw stops are in sync for that draw setting...

Neil

Thanks Neil this is what I was thinking but my stops are where they always have been ....back all the way.

I will check some spec measurements first but I was reading that maybe a few twists out of my string will help with the let off / draw length? Another thing I have my limb bolts bottomed out then backed of a 1/4 turn and am only getting 67 lbs. Also one other thing is that bith my d loop and peep seem to be twisted off center.
So the more I think about it maybe a couple twist made its way into the string.

Thoughts?

Thanks,
Mike

[L.O.S.T.Arrow]

Mike ...I would max limb bolts down snug hand tight and back off 1/8 is fine...one can shoot any bow maxed down but the 1/8 -1/4 is in case limb bolts cease we have a little play to work bolt...I use 1/8 and have zero issues...

THEN I would spec tune bow ..all specs...ATA ,BH Timing, Draw, poundage, cam/idler lean

Twisting cable brings up poundage fast..1 twist may generate 1-2 lbs on some bows.... generally two twists to string one to cable will equal specs minimally...as one brings up poundage reduces ATA etc

Twisting just string or cables to achieve any one spec will effect all specs...

This is a chart that shows what twists will do...I had made this up for Mathews Solo Cam bows but the princible applies to all bows...



Neil

[L.O.S.T.Arrow]

Just to add ..the reason a bow gets jumpy for a shooter after changes is timing of cam/cams may be off...[due to changed draw] the roll over wants to jump too quick...causing that jumpy feeling with any creeping...or with draw stops out it may be slight longer draw and as you settle into anchor it reaches roll over..resulting in same issue...

Its simple to move draw stop 1/8 to see if it improves or gets worse...that will tell you something...

But its best to bring bow into all specs first as described above...

Neil

[Mike_W]

Thanks for the help Neil I will check all of the specs first but this chart in this thread is what I am thinking.
Even the 1/4 turn I am out shouldn't loose three pounds. I'm thinking there are some extra twist to the string causing all this. According to this chart taking out a twist or two should increase draw weight and increase valley / let off.
When I get a chance I will check my ATA as this should let me know right away if I have a couple extra twists.

Thank you,
Mike

http://www.athensarchery.com/forums/...le-adjustments

[Lefty-Canuck]

Usually ATA is too long and cables require twists to gain on draw weight. Extra cable twists GAIN weight in general.

LC

[Mike_W]

Originally Posted by Lefty-Canuck

Usually ATA is too long and cables require twists to gain on draw weight. Extra cable twists GAIN weight in general.

LC

Yes or removing twists from STRING.

[L.O.S.T.Arrow]

Originally Posted by Mike_W

Yes or removing twists from STRING.

:d Very rare one Loosen's strings or cable only while tuning a bow...putting one to cable would accomplish what you are thinking plus bring that draw weight up... ATA in etc .. which is a result of strings settling or stretching!!

Neil

[Lefty-Canuck]

Originally Posted by L.O.S.T.Arrow

..putting one to cable would accomplish what you are thinking plus bring that draw weight up... ATA in etc ..

Neil

My point exactly . I know when one of my bows wasn't making poundage...first thing we measured was the ATA and it was too long, put in a couple twists on the cables and boom fixed.

LC

[Mike_W]

Originally Posted by Lefty-Canuck

My point exactly . I know when one of my bows wasn't making poundage...first thing we measured was the ATA and it was too long, put in a couple twists on the cables and boom fixed.

LC

Ah Ic I will need to do some measuring and see where I am.

[Lefty-Canuck]

Originally Posted by Mike_W

Ah Ic I will need to do some measuring and see where I am.

Have a look at this, page 38-40.

http://archeryhistory.com/archerytal...11510_rev2.pdf

LC

[Mike_W]

Ok so ata is 33&3/4" spec is 34"
Brace height is 7&1/8" spec is 7".
Pulling 67 lbs and valley seems short.....what should I do first untwist string?
Timing is curently on

[Lefty-Canuck]

Originally Posted by Mike_W

Ok so ata is 33&3/4" spec is 34"
Brace height is 7&1/8" spec is 7".
Pulling 67 lbs and valley seems short.....what should I do first untwist string?
Timing is curently on

Your brace height is likely increased because the ATA is a touch short...did you swap 70lbs limbs for 70lbs limbs? Usually a shorter ATA equals a heavier draw weight.

But I am far from an authority on bow tuning!

LC

[Mike_W]

Yes I swapped for 60-70 lb limbs same as prior.
I took four twists out of each cable and out of the string (2 on each end of both cables and string).
Brace height is bang on and ata is just a c hair short (33&15/16th) which is close enough. Four twist out of each string also brought my peep and d-loop back perfect?...Probably a coincidence.
Also played with my draw stops and the bow feels a bunch better. I will double check timing next time I get a chance. I also bottomed out both limb bolts and back out a 1/8 turn at your suggestion Neil, I dont know why but my marks on my limb bolts suggest each was backed out 3/4's of a turn.
Thanks to both Neil and Lefty for your help!

[L.O.S.T.Arrow]

Great job Mike!!!...When I spec tune a bow I will tune with ATA short ...that exact 1/16 you have...brace height will be slight same long...and slight over rotation on cam or timing...poundage will be hot...71-72 on 70 lb limbs...

Strings even if settlled...will settle more if bow is pressed and strings are worked on...

Within a target round..all Specs will fall 100% into specs..

On my personal bows I may even exaggerate the above and have the bow settle as above...that seems to be a sweet spot for many bows...


Just curious did you scale poundage?

Neil

[Mike_W]

No didn't scale the bow yet as I am not setup for that at my home.
I did draw the bow with the limbs bolts 3&3/4 turns out and man did that draw nice lol.

It is back to the nice smooth draw and solid back wall with a little creep that I am use to. I would estimate the poundage at 69#.

I will check the poundage and see how it settles and maybe put a twist back in if need be.