TWISTING CABLES UP TO GET 65LBS ON 60LB BOW

[BAYOUBENGALS]

wHAT ARE THE POSITIVES AND NEGATIVES OF THIS? IS IT DANGEROUS?

[littleal]

WARNING! Injury may occur by exceeding the rated limitations of the bow
I would NOT recommend it! There are possibilities of the bow Blowing up
AL

[JOE PA]

That would really depend on a few different things. If you are talking about twisting only the cables and not the string, then the increase in draw weight would involve the more forward rotation of the cams or cam. The difference in cam position could change the radius from the string track of the cam to the axle (pivot point) compared to the radius of the cable track. That would increase the draw weight without too much prestress on the limbs. It would also increase the draw length, so unless your cam or cams have modules or other draw length adjustments, you may just have a bow that is more difficult to shoot well and gives you other problems like shoulder stress, string slap, etc.

If you are talking about shortening the string and cables, then the extra draw weight is coming from greater limb prestress. Depending on the make and model of the bow, this could be a problem. If I' m not mistaken, though, on some bows, the difference between a 60 and 70 # bow is in the height of the limb pivots. If that is the case, then I don' t see where the added prestress of twisting the harness system could be all that dangerous. On other bows and limb systems, it could be much more of a risk.

I have been doing some experimentation with a bow that I put together. Trying out different harness lengths, I have had anywhere from 36 1/2" a2a and 6 1/8" brace, to 34" a2a and 7 1/4" brace. In the 34" configuration, the bow is quieter, recoils slightly less, and is more forgiving to shoot, at least for me.

Then again, my wife may come home some day to find me lying in a pool of semi-coagulated blood, too badly injured for medical science to save me from this bizarre experiment gone wrong![&:][&:]

I don' t worry about it when I shoot, though.

[Arthur P]

I don' t think twisting stuff up to get 65 pounds would hurt the bow either. Problem is what Joe points out. If you twist up the string to keep the same draw length, you also increase brace height. Higher brace height = less power stroke for a given draw. Less power stroke = less stored energy. Less stored energy = less speed and KE. It' s possible you could pick up a little bit of speed right before you hit the point of diminishing returns, but in my experiments I' ve never seen enough speed gain to keep pushing the bow past it' s design limit.

Now, quieter shooting, less vibration and more forgiveness... Those are the reasons I push the pre-stress on my bows a bit. When you' ve got ' em wound up tight, they sure don' t do a lot of vibrating.

[BAYOUBENGALS]

I had twisted up my string a couple twist to shorten my drawlength and had to twist my cables to get the cams back in time. I actually have them back at the original timing marks now. I am thinking about puting one to two more twist back on the cables, cause I think I held better. The cams were advanced about an 1/8" The bow is a patriot dual cam.

[JOE PA]

Maybe Vic (500 fps) will chime in on this one. He has talked a few times about advancing the cams on his Bowtechs to get more speed.[8D]