Speed loss

Discussion in 'Bowhunting' started by jrock, Jul 15, 2014.

  1. jrock

    jrock Well-Known Member

    Messages:
    403
    Joined:
    Mar 12, 2014
    I have a questions for any bow tweakers on the site.

    I have an insanity CPX, love the draw on it and it shoots awesome. I've had the bow for going on three years now. Bummer thing I've noticed is that I lost about 12 fps between year 1 and 2. Just put new Vapor Trail VTX strings on with bBwjax string sleeves instead of speed nocks (awesome Bowjax product BTW) and once the bow was in spec, I had no speed change. Didn't expect to with just a string change but the bows was out 3/16" on ATA and was hoping that brining it back into spec would fix it. You know, increasing the preload and all.
    I don't have a scale to measure the draw weight and Bowtech just says to take it to a dealer. I'm thinking it is limb relaxation. Thus I would have to shorten the ATA below spec to get the 70 lb draw weight back. As you all know in long range bow hunting, 12 fps is a big difference. Any thoughts before I contact bowtech again?
     
  2. dk260

    dk260 Active Member

    Messages:
    27
    Joined:
    Jul 6, 2013
    I'm having a hard time following you... At what time (after what change) did you notice the speed loss? I imagine you know this already, but check ATA and Brace height along with keeping the cables dead center in the timing marks before you call it in spec.
     

  3. jrock

    jrock Well-Known Member

    Messages:
    403
    Joined:
    Mar 12, 2014
    I noticed the speed loss near the end of my second season with the bow as I had to progressively adjust the pins.
    I have it set up now with the ATA 1/16" short on one side and 1/16" long on the other so average is 32". The cams are synced by draw stops and are within the timing dots but about 1/32 off of dead center. I have a 28" draw.
    I am going to put a couple twists into the cables tonight to make the longest ATA measurement 32" and see what happens. Thinking of just shortening the ATA until I get back to the original speed. Brace height is spot on. I did contact Bowtech and they said if the bow is in spec and shooting slow to have a shop send it to them to get it evaluated.