[bigdog02]

I know a lot of bow companies end up "fudging" their IBO speeds, so I am curious as to what real life speeds could be seen from bows in the reflex line, fred bear line, and others (I know mathews and bowtech and some other companies ring pretty true with their speeds already, plus they are out of my price range!)
For example, my Jennings CK 4.0 is IBOed at 300 fps, yet shooting a moderate 425 grain arrow I get an actual speed of 240 fps maxed at 70lbs with a 29 inch draw length. (2 cat whiskers, 1 brass nock, kisser button, string loop - only things on the string)

Anyway, just curious of what actual bow speeds could be expected from an arrow weight in that general area with bows from the reflex line (super slam, buckskin, timberwolf, highlander), and some of the new fred bear bows (code, instinct, element) or any other bows in that general sort of price range.

 

[tacdriver]

Speed!

Check out www.prairieshack.com , they have a speed estimater.
First click on Build your arrow and you will see the speed estimater,
just put in all the info and you got it, It is really close.

 

[bigdog02]

lol i visit that site all the time, how the heck did I miss that???

 

[Brown Hornet]

For example, my Jennings CK 4.0 is IBOed at 300 fps, yet shooting a moderate 425 grain arrow I get an actual speed of 240 fps maxed at 70lbs with a 29 inch draw length. (2 cat whiskers, 1 brass nock, kisser button, string loop - only things on the string)

Companies don't fudge their numbers like they used to. That being said.....your speed is fine. You loose about 10 fps per inch of draw you are under the IBO standard 30". So you are already down to 290 fps before you start. Then your arrow is 75 grains over IBO that is a huge chunk of speed. Then you have a ton of stuff on your string. You also have to ask is your bow tuned to get the best performance you can from it? They don't come from the factory already setup.

 

[bigdog02]

At the prairieshack site, I am just reading the IBO standards, so it seems pretty logical to equal out my speed.

IBO speed is measured with bow set up at 70 lbs Draw Weight, at 30" AMO Draw Length, shooting 350 grain arrow (5gr per pound of Draw Weight - 70lbs D/W x 5gr = 350gr)

Calculation:
One pound difference in Draw Weight = +/- 2 feet per second
Each 10 grains difference in arrow weight = +/- 3 feet per second
One inch difference in Draw Length = +/- 17 feet per second (not 10 fps as is commonly used)
We tested this method of estimation both physically and mathematically. We used data from different models of Hoyt, Mathews, Bowtech, Martin and PSE.
The estimate was accurate within +/- 5 feet per second. We found that bows at the lower end of efficiency gave bigger deviation than high efficiency bows

Advertised by Jennings at 300. Take away 17fps for 29 inch draw puts me at 283. 75grains over the IBO arrow equals 22.5fps gone to put me at 260 fps. That leaves 20fps lost to junk on the string, draw weight actual number and general tuning. Makes pretty clear sense.

As far as tuning goes, the shop I bought it at set me up with it, then I went to a second shop to get it setup for me again when it wasn't feeling right from the first shop. I would hope by now it is somewhat tuned, but I am sure it isn't.
Thank you for the responses so far.