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View Full Version : Speed lose?



cyclepath
09-21-2011, 06:33 AM
OK, lets talk speed lose in bows. I know that some speed is lost do to how much poundage the bow is set at. How much speed is lost shooting 60#compared to 70#? Does this increase as the poundage drops, say shooting 50# compared to 60#? In other words would you loose more speed between 50 to 60# or between 60 to 70#? What over all speed would you loose shooting 50# compared to 70#? Of course this would be done using the same grain arrow. Do these figures work the same with all bows or more so with speed bows? What say you?

RLW
09-21-2011, 07:36 AM
OK, lets talk speed lose in bows. I know that some speed is lost do to how much poundage the bow is set at. How much speed is lost shooting 60#compared to 70#? Does this increase as the poundage drops, say shooting 50# compared to 60#? In other words would you loose more speed between 50 to 60# or between 60 to 70#? What over all speed would you loose shooting 50# compared to 70#? Of course this would be done using the same grain arrow. Do these figures work the same with all bows or more so with speed bows? What say you?
From my few personal bows ranging between 50lbs to more than 80lbs over the last +/-15 years I've found that they typically ranged from 2.0 to 2.5FPS/LB........my current Bengal, between 60 - 68lbs, worked out to 2.47fps/lb.
Each bow and it's efficiency within a weight range, the arrow weight and various set-ups would be different to some extent........just like IBO ratings are different between bows for same draw weight, so would this loss or gain (to a much lesser degree).

This reminded me of a book I have from about 1990 called Balanced Bowhunting by Dave Holt. In it talks of improving trajectory and one of the things mentioned is draw weight, where he states "Arrow speed will increase approximately 1 3/4 FPS for each pound of draw weight that is added".
His example is discussing an old round wheel bow set at 55 lbs, shooting a 620gr arrow at 170fps. Bow efficiencies have improved a bit since then.

MLN1963
09-21-2011, 08:19 AM
His example is discussing an old round wheel bow set at 55 lbs, shooting a 620gr arrow at 170fps. Bow efficiencies have improved a bit since then. And arrow weights have gone down, way down.

gravedigger
09-21-2011, 08:38 AM
there are so many factors in speed gain/loss.single cam and dual cams and what cam you have,strings+ what is added to them.pounds of draw,arrows,silencers,rests,ata,tunning,ect.i dont go by speed anymore.im going with arrow weight and setup.i would rather have a 500 grn and shooting 250 fps then a 350 grn arrow shooting 300 fps.im going to be turning my bow down to 60# and try and shoot 450+grn arrow for a hard hitting set up...ok maybe 65#.lol.

73# i am at will some time down the line kill my back and sholder and i want to be shooting for many years to come.

Skbengal
09-21-2011, 01:43 PM
Your information brought up something I've wondered about.If you lose 1fps/3grains on the string how is it they claim speed knocks add speed?Just curious.

cyclepath
09-21-2011, 06:15 PM
It's said to correct one's spelling is rude or demeaning. Okay, I'll accept that. Heck, I'm a nice guy. If I had any friends you could ask them.

WOW, I've pulled a few of these out of my bag of late. To much of a hurry this morning. Thinking loss and loose at the same time, oh well;)