A couple of Chrono numbers

[zwickeyman]

I have a very consistant draw and a decent release and these numbers are pretty darn close to what I figured they would be.

   64" ACS 54# @ 28"     drawn to 28" 3 under     Hunting string with silencers  

2216   125 gr head  526 gr.  9.7 gpp    184 fps

2215   125 gr head  484 gr   9.0 gpp    191 fps

2016   100 gr head  440 gr   8.1 gpp    199 fps

I know I like seeing peoples numbers so I thought I would throw some out there.

[vtmtnman]

70's Bear grizzly,58" 50@ 28" drawn to 28,175gr tip on a full length GT 35/55 with 3 5.5" nanners,split finger release and cat whiskers on the string gave me 176 when I ran mine.Might be shooting a bit slower now with my 2213's though.

[8888blk]

50#@30" ACS 525gr Easton Axis 400 @ 31 1/4" long 3 under 182fps  

[Boom Stick]

Hey Zwikey,  is there a difference if you shoot split fingered?  I'm curious what,  if any,  difference that would make.

[zwickeyman]

Boom Stick,

 It's funny you ask because I shot both ways today and for me 3 under was a consistant 2 fps faster. Goes to show another reason to use what ever works best for you.

[Boom Stick]

Thanks Zwikey,  that's interesting.  

Have you tested with different brace heights?
Is a lower BH actually faster although it sacrafices poundage?

If you have a scale, it would be great to see the numbers compairing the same bow's speed at a couple different brace heights.  (BH/#/fps)

[Blackhawk]

BS,

you say, "Is a lower BH actually faster although it sacrafices poundage?"

Just curious, but how does lowering your brace height sacrifice poundage?  I had always thought lower brace height made for "faster" bow.

[Boom Stick]

Originally posted by Blackhawk:
 I had always thought lower brace height made for "faster" bow.

That's the rumor but not everyone agrees.  I personally would like to see the numbers because I've heard both sides.  

-A higher BH stacks more power in the limbs and increases it's poundage, giving it more speed

-A lower BH keeps the string in the nock longer giving it a longer "power stroke" and more momentum and greater speed.

The second point (seems like it) would be true if you compare 2 bows with the same weight but at different brace heights.  But if you are just using ONE bow?

I'm on the higher BH/more poundage side of the fence,  but it's just a feeling.  I never tested it with a chrono.

[BernieH]

I don't see how a higher or lower brace is going to change the bow's draw weight if drawn to the same place on your face. The weight at full draw will be the same in both cases. The higher brace will produce more weight at the beginning of the draw due to higher tension and the lower brace will start out lighter because of less tension but both will end up at the same draw weight.  The lower brace will produce more speed because of the longer power stroke.

[Boom Stick]

Not too sure about that Bernie but that's the great thing about testing things out.

I'd bet if you measured the bow from tip to tip at full draw,  the one with the shorter string (higher BH) would measure less than the one with a longer string (lower BH).  The tips of the higher BH would probably come back further too.

I never actually measured it from tip to tip at full draw though.  Every time I've tried,  I dry fired the dang thing!    

[TradBowyer]

for all the more difference we talk about for brace height (1-1.5") a shorter brace height will give you more speed but not much...maybe 2-3 fps (in my testing anyway). This is due to the longer power stroke you get (force draw curve). Raising the brace height will not affect draw weight (theoretically it may but so small that its "negligable") because the limbs tips are always going to end up the same place for a given draw length regardless if the brace height is 5" or 10". You can verify this if you have a tiller tree. draw the bow to 28" and look at where the limb tips are. Lower brace heights basically mean the limb tips have to move a greater distance to get to that ending point than they do if the brace height is higher thus resulting in higher speed numbers but again, in my testing the differences have been so small that its not worth even considering.

[zwickeyman]

Tradbowyer is right. Don't worry about brace height for speed because it's very minor. Brace the bow at the quietest spot.

[leftybearfan]

62" d/r longbow, 47#@ my 30"draw, 31.5" Heritage 150s with 125 grain tips (512gr total weight), 175 fps.