IBO vs. AMO for bows
 

Does anyone have the IBO speed ratings for bows and the corresponding AMO ratings? For instance if a bow shoots 311 fps IBO, what is the corresponding AMO rating in fps?

RE: IBO vs. AMO for bows
 

tech forum please!

RE: IBO vs. AMO for bows
 

Speed Rating IBO vs. AMO
There has been a lot of confusion over bow speeds in recent years, as manufactures all vie for the top spots on the velocity charts. In an attempt to keep the playing fields level and give consumers a basis for comparison, two different rating methods have been adapted. IBO (International Bowhunters Organization) and AMO (Archery Manufacturers Organization) are the two standards used to compare speed. While they are standard, they do differ drastically from each other.

AMO speed is figured using a bow set up at 60 pounds of draw weight, 30 inches of draw length and using a 540-grain arrow.

IBO speed is figured using an arrow that weighs 5 grains for every 1 pound of bow weight. Example: A bow set at 70 pounds of draw weight with an arrow that weighs 350 grains (70x5).

As you can see, the rating system is drastically different for each method, which explains the wide spread in velocities between AMO and IBO speeds. IBO is using a higher draw weight, a drastically reduced arrow weight (compared to AMO) and an undisclosed draw length (longer draw lengths translates to more speed). Since many archers have a "need for speed" attitude, it is obvious why bow manufacturers choose to advertise the IBO speeds of their bows but for the best comparison AMO is a more consistent litmus test.