RE: Bow Question
IBO stands for International Bowhunters Organization.
AMO stands for Archery Manufacturers Organization.
Both of these group established a standard set of guidlines for measuring a bow's speed.
For example, when IBO speed is listed for a certain bow, it is measured using a 30" draw length, 70# draw weight and 350 grain arrow or a minimum of 5 grains of arrow weight per pound of draw weight. IBO speed will always be the higher listed speed.
AMO standard is measured at 60#, 540 grains of arrow weight, and 30" draw length. Most bow manufacturers used to list both IBO and AMO ratings for their bows. Now it seems like they only list IBO speeds.
Brace height is the measurement from the deepest part of the throat on a bow's grip to the string. As a rule, higher brace height bows tend to be more forgiving and accurate but at the expense of speed loss.
Hope this helps.