Just the facts: Precise new testing equipment blows away the smoke and mirrors.
Like many folks, I eagerly await this annual show where the majority of manufacturers in the bowhunting industry introduce their new products. An air of excitement always surrounds this event, and it's great to be among the first to view the new offerings.
When the bow season ends, I become a technical nut. So it's not surprising that I was fascinated by the first-time appearance of the $45,000 Instron machine Mathews brought from its research and development facility in Sparta, Wisconsin. I love testing bows and have plenty of equipment for that purpose. But comparing what I have to the Instron machine is like comparing a Cadillac to a Leer jet. This machine can do more in mere minutes than I can do in hours. And it does it more precisely.
The Instron machine automatically draws a bow while feeding data to a computer at each 100,000th inch interval. These data are displayed on a computer screen, in real time, during the bow-drawing process. You can watch as the force draw curve is plotted. In other words, it is easy to see the bow's precise peak draw weight, the exact draw length, the holding weight, and even the length of the valley.
The machine then reverses the process and plots the let-down curve. Comparing these curves clearly shows the difference between ATA letoff and effective letoff. As soon as the bow is back to its brace height, the computer displays the total amount of energy the bow stored and the percent of letoff (both ATA and effective).
Mathews also brought a shooting machine, a chronograph, and an electronic grain scale to the ATA show. With data from this equipment plus the Instron machine, the company can easily conduct super-accurate arrow velocity and dynamic-efficiency tests.
And with all the data so visible, it cannot fudge the numbers. In fact, Gary Simonds, Mathews' head engineer, declared the equipment's location a "smoke and mirrors-free area." My hat is off to any company that will go to this effort and expense to prove that its products perform as advertised.
When Simonds wasn't busy, we conducted some velocity tests with bows that had considerably different letoffs. The first test was conducted with two Mathews Black Max bows, set at 70 pounds and 30-inch draw lengths. One bow had a 73-percent ATA letoff and the other had a 42.3-percent ATA letoff. The 73-percent letoff bow shot a 350-grain arrow at a velocity of 330 feet per second (fps). The bow with the 42.3-percent letoff shot the same arrow at 339 fps.
The second test was conducted with two Mathews Black Max models, set at 60 pounds and 30-inch draw lengths. The first bow had a 60-percent ATA letoff and shot a 540-grain arrow at 253.5 fps. A similar Black Max with a 42-percent ATA letoff shot the same arrow at 258.2 fps. It was fascinating to see the differences in arrow velocity between these bows, when the only noticeable change was percentage of letoff.
This is just one of many tests that can be conducted with such precise equipment. Overall, this was a fabulous chance for dealers and writers to educate themselves further on the workings of modern bows. I certainly hope Mathews and other manufacturers continue to provide such educational opportunities at the ATA Show.
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|Date:||May 15, 2003|
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