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- - IBO Speed (https://www.huntingnet.com/forum/bowhunting/85268-ibo-speed.html)

I am a little confused. I am realtivly new to bow hunting, first year. I was looking at a new bow and it lists the speed as 310 fps. I was talking to my hunting partner about it and he asked if that was IBO speed. I looked at him with a "huh" :eek:look on my face. He couldnt explain it either, had heard that the FPS and IBO are different.

Can some one explain this to me? This is probably a very basic thing, but I have never heard it before.

It is the speed of the bow shooting the following:

350 gr. arrow
70# draw weight
30" draw

This way you can compare numberous bows and figure out who inflates their numbers the most.:D

FPS means Feet Per Second and it's just the unit of measure. For example the bow you are mentioning most likely had an IBO speed of 310 feet per second. Now IBO speeds are measured at:
350 gr. arrow
70# draw weight
30" draw

as btomlin already mentioned. So if you go up or down in arrow weight or in draw length or in draw weight it is going to effect the actual speed that the bow will be shooting with your particular setup. Also, if you add accessories to the string it will also decrease your speed.

So using this, how could you tell if the number was inflated? I guess I dont understand. Sometimes I need to be hit in the head with a brick before it sinks in.

The bow I am looking at is from Cabelas. it is the Cabelas outfitter series PL1.5. It says IBO:310 FPS.

Now according to another thread of bow and bow hunting terminology IBO means International Bowhunters Organization. Are they the governing body that determines bow speed?

Sometimes they are "inflated" becasue sometimes, at least I have heard this, they are getting the measurement by shooting blank arrows, ie no fletching. And of course it is a bare bones bow as far as silincing stuff and the like.

Ahh, I get it now, see what I mean aboutthe brick thing.

So in order to obtain 310 fps I need to shoot
350 gr arrow
70# draw weight
30" draw lenght

I got siad the blind man as he picked up his hammer and saw. Thanks guys.

No problem those were reasonable questions. Seems like you got it pretty quick to me.;)

I try. I try even harder when I dont want a bunch of guys thinking I am an idiot.:D
I imagine that they would want to inflate the fps in order to try and draw more sales, huh?

Some do but many users are getting to savy these days so it seems they have gotten more realistic in the last few years (at least it does to me).

One more thing to add:

The LAST thing I would look at if I was buying a new bow would be the IBO speed. There are many things that are way more important than arrow speed.

Fit and Feel should be the most important consideration when buying a bow.

Right, I realize that. It was one of the factors that caught my eye. Comfort far out ways speed in my book. It could be the fastest bow on the planet, but if it doesnt feel right in my hand, I wouldnt even consider it.

check out this link

http://www.huntersfriend.com/bowselection.htm

Lots of good info here.

Paul

Couple of points:

- IBO the group has NOTHING to do with IBO speed ratings. Its named that because IBO 3D rules state 5 gr/lb arrow weight. IBO the group has nothing to do with it and is NOT a certifying body, nor is it an industry standard. AMO speed (540 gr arrow at 60 lb, 30 inches) IS an industry standard, but results in a MUCH lower speed so isn't as "cool" looking as IBO spped. Your "real" speed will be somewhere between em probably.

- the IBO speed is VERY hard to achieve. Everything you do to a bow to make it shootable slows it down, anything on the string, peep, loop, nock point etc, slow it down.

- 350 gr arrow at 70 lbs is pretty tough to do without going underspined and very tough to do with a broadhead due to BH weights.

Use the IBO rating as a comparison only. If one bow is IBO rated at 315 and another at 295 you can tell which will be faster, but don' t be suprised if you don't get that number.

My bow is IBO rated at 305, I shoot it at 30 inches (IBO does to), 65 lbs (5 under IBO) and 400 grain arrow (50 over IBO), with a loop and peep sight. I get 270 fps.

--Bob