Buying a 200 + fps trad bow does not mean you will actually get that when you shoot it. There are so many variables that come into play.
There are two "standards" for testing bows: IBO and AMO.
IBO is 70 lb peak weight at 30 inch draw w 350g arrow ( 5g/lb ). AMO is 60 lb peak at 30 inch draw w 540g arrow ( 9g/lb ). Usually done in a machine w a mechanical release.
For trad bows, you have to adjust for the difference between the 28 inch "peak" marked on the bow and the actual weight at 30 inches. Some just test w the actual weight at actual draw w a finger release for a more real world result.
For example:
Groves 1999 Spitfire Magnum recurve, 60lb@28, 12 strand Dacron string: IBO 249 fps, AMO 211 fps. The actual weight at 30 inch draw is 65 lbs though. At a 28 inch draw, more like 194 fps w 540g arrow.
I have a 1972 Groves Spitfire Magnum, 41lb@28. W a 12 strand Dacron string and finger release at 26 inch draw, I get 165 fps w 382g arrows.
So where did I loose 29 fps? Say about 2 fps for the extra 13g of arrow, about 5 fps for the finger release, 17 fps is in the shorter draw/less draw weight, and 5 fps for the relatively heavier string (they used 12 strands for a 60 lb). Sumthin' like that.
I called Martin and they said a 60 lb Savannah does 180 fps w a 540g arrow and FF type string. My 35 lb Savannah did 155 fps w a 315g arrow at my 26 draw w a Dacron string. So 2 inches of draw length, fingers, and a Dacron string cost me 25 fps there.
Black Schwarz tests for Trad Bowhunter and Bogensport magazines. He got 177/183 fps from a 51 lb Bear TD and 459g arrows at 28 w fingers and Dacron/FF strings. From my 35 lb Bear TD I got 165 fps w 315g arrows at 26 w a FF string and fingers. So 2 inches cost me 18 fps there.
Not that speed is everything. I have shot slower bows that I like better than faster bows that I didn't like... :wink:
There are two "standards" for testing bows: IBO and AMO.
IBO is 70 lb peak weight at 30 inch draw w 350g arrow ( 5g/lb ). AMO is 60 lb peak at 30 inch draw w 540g arrow ( 9g/lb ). Usually done in a machine w a mechanical release.
For trad bows, you have to adjust for the difference between the 28 inch "peak" marked on the bow and the actual weight at 30 inches. Some just test w the actual weight at actual draw w a finger release for a more real world result.
For example:
Groves 1999 Spitfire Magnum recurve, 60lb@28, 12 strand Dacron string: IBO 249 fps, AMO 211 fps. The actual weight at 30 inch draw is 65 lbs though. At a 28 inch draw, more like 194 fps w 540g arrow.
I have a 1972 Groves Spitfire Magnum, 41lb@28. W a 12 strand Dacron string and finger release at 26 inch draw, I get 165 fps w 382g arrows.
So where did I loose 29 fps? Say about 2 fps for the extra 13g of arrow, about 5 fps for the finger release, 17 fps is in the shorter draw/less draw weight, and 5 fps for the relatively heavier string (they used 12 strands for a 60 lb). Sumthin' like that.
I called Martin and they said a 60 lb Savannah does 180 fps w a 540g arrow and FF type string. My 35 lb Savannah did 155 fps w a 315g arrow at my 26 draw w a Dacron string. So 2 inches of draw length, fingers, and a Dacron string cost me 25 fps there.
Black Schwarz tests for Trad Bowhunter and Bogensport magazines. He got 177/183 fps from a 51 lb Bear TD and 459g arrows at 28 w fingers and Dacron/FF strings. From my 35 lb Bear TD I got 165 fps w 315g arrows at 26 w a FF string and fingers. So 2 inches cost me 18 fps there.
Not that speed is everything. I have shot slower bows that I like better than faster bows that I didn't like... :wink:
