Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: 40 fps slow!!!

  1. #11
    Junior Member
    Join Date
    Mar 2011
    Posts
    28
    Post Thanks / Like

    Default

    Could it be my strings and cables? If so, what are the best to get? And size?

  2. #12
    SonnyThomas
    Guest

    Default 40 fps slow!!!

    Wet and cool outside so I read up here.

    Seems everyone told you correctly.
    For sure I'd get the draw weight down. If you don't have a press then take it a shop and have them back off the cables and strings. They can adjust timing and correct draw length in the process if need be. As for the cams, yes, they should be free and even spin. And yes, the outer bearing moves with the cam and the inner race is only needed, no spacers. My Shadowcat has no spacers. So contact Martin if not free wheeling.

    Actual fps and program fps can be quite different.

    I've put up the following several times. You start with factory IBO fps and add or subtract from IBO specs.
    2 fps / 1 # of Draw Weight
    10 fps / 1" of Draw Length
    1 fps / 3 grains of arrow weight
    1 fps / 3 grains of weight on the string

  3. #13
    Junior Member
    Join Date
    Mar 2011
    Posts
    28
    Post Thanks / Like

    Default

    What length should my strings and cables be?

  4. #14
    SonnyThomas
    Guest

    Default 40 fps slow!!!

    Quote Originally Posted by rdmwc View Post
    What length should my strings and cables be?
    Look up on Martin website - they have a listing for older bows.

    Here's the thing, ata does not have to be to specs. ata is a approximate. The real spec will be when max listed draw weight is achieved. so ata could be long to get draw weight down. If I remember correctly the industry standard tolerance for ata is +/- 3/8". Beings most hit max poundage at +/- 1/8" I'd say they are doing something right.

  5. #15
    Junior Member
    Join Date
    Mar 2011
    Posts
    28
    Post Thanks / Like

    Default

    My ATA is at 34.5 I remember seeing somewhere the ATA was 34" but now see dyes say 35..? I will look it up. My bh was dead on, but now is 3/8 long.

  6. #16
    Senior Member
    Join Date
    Dec 2008
    Location
    Port Washington, Ohio
    Posts
    543
    Post Thanks / Like

    Default

    The string should be 57" and the cables should be 40.5". AtA should be around 35" and brace should be around 6 1/4". The brace and AtA are appox. specs only. Get the string/cables set to spec and the cams timed and go from that point.

    The cams should rotate freely, if you take the string and cables off you should be able to spin them with your finger and they should make 2-3 revolutions before stopping. If they stop almost right away they are too tight and you will lose a lot of speed.

    Advantage Custom Strings

  7. #17
    Junior Member
    Join Date
    Mar 2011
    Posts
    28
    Post Thanks / Like

    Default

    well, i took off all my cables and string. they were all within a 1/16 of an inch! shocked me! i put some nylon shims by the cams so that the only thing touching is the axle race( paper thin nylon washers, the cams now spin very freely with no slop!) i am now timing the cams according to the cat cam timing thread on archerytalk.com

  8. #18
    Junior Member
    Join Date
    Mar 2011
    Posts
    28
    Post Thanks / Like

    Default

    well, thanx for the help everyone, not sure what happend, but i put it all back together and all the measurements are the same. but im now shooting 309fps. i kinda want to try to get that bh down to the 6.25 from the 6.5 its currently at, but i dont think i will gain much. and am afraid i will not get it set back to how it is now. what you think?

  9. #19
    Senior Member
    Join Date
    Jun 2009
    Location
    Melbourne Australia
    Posts
    380
    Post Thanks / Like

    Default

    Quote Originally Posted by rdmwc View Post
    well, thanx for the help everyone, not sure what happend, but i put it all back together and all the measurements are the same. but im now shooting 309fps. i kinda want to try to get that bh down to the 6.25 from the 6.5 its currently at, but i dont think i will gain much. and am afraid i will not get it set back to how it is now. what you think?
    My advice would be, that if you're happy with the way it's shooting, leave it alone. If you do decide to alter things, just make a note of exactly what you did, so you can get back to square one.

  10. #20
    Junior Member
    Join Date
    Mar 2011
    Posts
    28
    Post Thanks / Like

    Default

    I'm averaging 301 fps. With a d loop and 6 whisker silences... thanks for the help guys!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •