July 09, 2009
By Scott Bestul
Fresh back from the 4th of July holiday weekend, I received a letter from a Mr. D. Keezer, who had taken the time to read the FS bow test, which appeared in the magazine’s July issue. Mr. Keezer noted that he’d also scanned recent advertisements from bow companies, and that these companies were posting arrow speeds significantly faster (in one case 47 feet per second) than the ones we posted in the bow test.
Were these companies, Mr. Keezer wondered, making false advertising claims?
The answer is a qualified “no.” When bow manufacturers post the speed of a bow to post in ads, they are testing the bow according to IBO (International Bowhunting Organization) standards. This apples-to-apples test requires a manufacturer to shoot a 350-grain arrow from a bow set at 70# with a 30” draw length. That’s the “no” part of the answer.
Here’s the “qualified” part. Most bow makers do adhere to IBO standards, but they may also tweak their test to achieve the hottest arrow speed possible. They’ll fling a bare (unfletched) arrow shaft, and use a naked string; no nocking point, and certainly no peep sight or string silencer, all of which will slow an arrow. If possible, they’ll set the bow at the lowest option for let-off (65% vs. 80% for example), forcibly over-draw the bow, and shoot dozens of arrows. Then they’ll post the best FPS rating, rather than an average.
In a nutshell, bow makers wring every possible ounce of speed out of a test model, so they can advertise and appeal to all the speed freaks out there. Does that mean the bow you buy will match the arrow speed pronounced in an ad? Highly unlikely, if not impossible.
But here’s the main reason the speeds in the FS bow test were so far below manufacturer’s claims. Every bow we shot sported a 28-1/2” draw length; we chose this draw length as an average among our test-team members, since we were as concerned with how a bow felt to the shooter and wanted as natural a fit as possible. This draw-length drop results in an automatic loss of some 15 fps. Also, the arrow we shot through our chronograph weighed 446 grains, another automatic speed deduction, since heavier arrows are slower than lighter ones. And who knows? Maybe our chronograph wasn’t calibrated perfectly.
Basically, the only factor of the speed equation we were interested in was relativity; given our setup, where did each bow rank in arrow speed? And we achieved that goal. If you haven’t guessed by now, speed is only factor in my decision about which bows are “best.” Sure, I appreciate a decently-fast bow...but as a hunter I’m far more concerned with a half-dozen factors that have to work together so a bow feels right to me.
And that, my friends, is my long-winded answer to Mr. Keezer’s question!