JagDog

My setup (3 mths ago): LX 65 lbs - 29" draw - 80% letoff - Trophy Taker (long bar) - peep (no cord) - string loop - Goldtip 3555 - 26 3/4" - 75grn tip - 4" feathers = 305fps:
Since then I have changed arrows and poundage. I did this to achieve 260fps. I shot it though my chrono, it went 255fps. I checked my chrono, it is fine, no other changes, yet I lost 5fps.
Problem: I cranked the limb bolts till they stopped, then backed it off one full turn. But now with the above Goldtip I only get 282fps.
Owners manual: 3 to 4 lbs per turn not to exceed 5 full turns out. Easy enough, but does not calculate out right. 5x3=15+60=75lbs or 5x4=20+60=80lbs. It could even go the other way if max is 70lbs.
Question #1: How do I know what the poundage is without a scale?
Question #2: Why am I going almost 23fps slower?
Question #3: Could it be the Zebra string? ( I shoot a minimum of 24 arrows a day)
Thanks in advance...

Droptines

Not sure what you have going on,,,sounds like something is stretching,,bus cable or your string,,tune your cam.Make sure it' s not over,,or under rotating.Very easy to do with the MATHEWS cams.
P.S.
{Buy a hand held scale.WORTH every penny}

CBM SC

Check your cam timing......your cable has probably stetched slightly. The two small holes in the top and bottom of your cam should line up and be parrallel to your string.

And none of the LX' s I have seen are actually pulling 70 # ......mine pulled 74# new and was a little out of time.....re-timed it and it pulled 76#. Seen about 4 others and all pulled between 72-76 # . Also ....typically all my previous Mathews dropped about 3.5 # per full turn.......this LX drops about 5 lbs per full turn !!

Droptines

WOW,,I think 76 lbs.,on a smooth drawing cam, like the LX, is PERFECT [:-]

Dalejbrass

Jagdog,

I hate to say it, but the Zebra strings on the new Mathews bows are junk!!!! I have owned three mathews bows and never had a problem until I got my LX. My string continually stretched. I finally broke down and put a Winners Choice string on it and have not looked back.
I would have to agree with everyone else......you should check for string stretch and cam position.
I would also recommend that you shoot a 5575. The 3355 spine is too weak for the poundage you are shooting! This may also be creating some of your problems.

JagDog

CBM SC
Check your cam timing......your cable has probably stetched slightly. The two small holes in the top and bottom of your cam should line up and be parrallel to your string.

JagDog
Not sure about what you are saying. Can you try to explain a little different? I looked but dont understand. Is there maybe a web page with some more info?

Dalejbrass
I would also recommend that you shoot a 5575. The 3355 spine is too weak for the poundage you are shooting! This may also be creating some of your problems.

JagDog
Since then I have changed arrows and poundage. I shoot Terminator 4560 now for hunting.

CBM SC

Man,....... I think Nub has a picture showing a straightline cam' s timing marks which are the same as the LX' s HP cam marks !! I' ll try again.......the cam has 2 small holes about the size of a BB .....one above the axle and one below. The top hole has the cam identification number stamped beside it.....SLHP-*** !
Those two holes are supposed to line up and be parrallel to the string on your bow so without a picture it' s hard to show you. You can take a peice of string and tie it in the bottom hole and run it the length of your bow , parrallel to your string. The string should pass directly over the top hole in your cam......if not ....it' s out of time and all you probably need is the cable twisted a little !!

tm

Not trying to knock your setup, but a 35/55 is waaaaayyyyyy underspined and with them being that short they are probably too light for that poundage. The LX likes stiff arrows and will probably shoot 55/75, but 75/95 might be better. The stiffer arrow may also give you more speed as it won' t flex as much. For instance I had to go with 3-71 ACCs to get the most out of mine, 3-60s would shoot, just not as good. I' ve had mine since April & shot it quite a bit with no string problems yet, did have to reserve the cable tho.

JagDog

Thanks CBM SC
I took it to the bow shop today and yes an 1 1/2" difference. We tightened the cable three turns to find out it was to far. Two turns and it is back in time. Didn' t help the speed any.
So that problem is solved. Next...

Question #2: Why am I going almost 23fps slower?

CBM SC

Jagdog...........??????? If your cam was out 3 turns or even two .....you would have to have been losing some speed. And 5 lbs in draw weight would equal about 10 fps !!
I would check all your measurements !!!
Your ATA should be 35 3/4 " .Your brace height should be 6 5/8 " . And your just had your cam re-timed !!
If all that is correct and you haven' t made any other changes to your bow or arrows........I' d have to guess it' s a problem with the chrono. Make sure you have adequate lighting . I would put a new battery in it.....I would not use the 3555' s(because the are way underspined and under weight for your warranty and probably flexing a lot as they pass through the chrono- giving different readings). You need to keep your arrow weight to 5 grains per pound and a GT 5575 at 27" with a 100 grain tip and feathers barely gets it !! But your bow should be pushing one of those about 285-290 fps if everything is tuned well !! Unless you have a lot of stuff on the string(?) !! Good Luck !