I have put the old rubber string silencers on my bow string and they helped a ton. I was wondering how many fps I am loosing with these.

If by "old rubber" you mean cat whiskers, a safe bet is between 3-15 fps, depending on how you installed them, if you did any trimming, how close to the center of the string, what kind of bow you're shooting, how heavy an arrow you are shooting, etc, etc...

How much FPS loss, or specifically transferable energy loss is primarily a matter of how much the object(s) attached to the string weighs and how close they are to the center of the string.

If they weigh 30 grains each, that's 60 total grains. If you are shooting a modern bow near IBO weights, you may well lose more than if you are shooting a much heavier total grain weight "hunting" arrow.

How much drop are you experiencing with your pins? Probably not much, and not worth worrying about, especially if it is on a hunting bow where silence is more desireable, to a point

Rangeball--6.11 AT 232.0

Rangeball,
Yes I am talking about cat wiskers. Where abouts should I mount them on string and how should I trim them? Secondly, would you recomed something else like the string leach or tranchalers?
I am shooting a Jennings Trophy Master 64# w/ Alm. arrows.
Thanks for the help.

Generally, the closer to the string, the more they silence, and the more speed you lose.

I'm guessing that if you aren't shooting a super light aluminum, chances are you are flinging a fairly heavy arrow by today's carbon monopolized standards, and the fps loss is probably on the low end of the above guesstimate. Trimming simply reduces weight, so less fps loss, but also less noise silenced...

If you aren't noticing an appreciable drop in your pin settings, I wouldn't worry about it. Speed is more about trajectory than it is penetration, within a certain range.

Same goes for RWK...

HUH?.....the closer to the string?
do you mean the closer to the serving?

the closer to the cam and or idler the less speed loss.

That sentence was missing the words "center of the".

Sorry.

I read in a bowhunting magazine that you lose about 10fps to each item you add to your string.

nubo

I would tend to disagree with that, Nubo, only because I can't see losing 10 fps over something small as opposed to untrimmed Cat Whiskers.

I would say a safe bet would be bewteen 3 and 15 fps.

I know all bows are different but we just performed a test on a diamond hornet at the shop to answer the question you were asking. The bow was set at 30" draw 75 lbs shooting a 348 grain arrow at 316 fps with string loop only. After adding cat wiskers the speed was 314 and after adding the peep(tru peep) the speed was 312. We tie the cat whiskers on with fast flight material approx 3" from the cam and idler wheel and trim them so that the whiskers are about 1½" long.