Product Profile: Prime Bows by G5

January 13, 2011

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g5 prime bow"You're only as good as you can measure."

That sage advice from Leo Grace, a self-taught engineer and founder of Grace Engineering—the predecessor of archery industry innovator G5 Outdoors—has remained in the hearts and minds of G5 staffers since the day the cutting-edge archery company was launched by Leo's descendents, including son Louis and his sons Matt and Nate, back in 2000.

And recently, those wise words have especially impacted Leo's grandson Nate Grace, the current head bow designer for Prime—a new premium bow company that has unveiled what looks to be one of the most significant advances in bow technology since the single-cam bow. At the epicenter of these ground-breaking bows is a unique new cam system, and a complementary, flexing titanium cable guard—exciting new technologies that work together to virtually eliminate bow torque and greatly enhance tunability and consistent accuracy.

By most any measure, what Prime has accomplished is no easy feat. Significantly reducing bow torque—a legendary accuracy-eroding bugaboo—goes a long way toward eliminating the primary cause of inconsistent "right and left" arrow impacts experienced with most all of today's compound bow designs. The "pulling to the side" of the cables, and "off centering" of the limbs—which Nate Grace explained are inherent in most every compound—induces cam lean and creates inconsistent nock travel.

For further evidence of this phenomenon in today's compounds, Grace related, all you have to do is glimpse your current bow’s sight window. You'll likely see your sight pins are "off center"—right-handed bows will have pins left of arrow centerline. More evidence is found when you research the reasons for solid-limb failure, another fairly consistent industry problem. Testing has shown Grace that most of today's premium bow limb designs would last nearly indefinitely—if flexed perfectly "in line" each time. But that's not what happens. When you introduce cam lean and limb twist into the equation, limb life is greatly decreased, and cracking and failure can be relatively common.

So how, exactly, are Prime bows different? It starts with their dual Parallel Cam system. Physical appearance resembles two cams "sandwiched" together (both top and bottom); you'll also note the string yoke coming off the cams, and the cable that rides down the precise center of the unique cams. What's even more unique is the resulting performance of this seemingly all-too-simple solution. The design came to Nate Grace a few years ago as he recovered from a blown Achilles tendon, an injury that kept him from a long-awaited mule deer bowhunt and put him off his feet for most of the fall.

"I was soaking my foot in the bathtub when it came to me," he remembered. "I suddenly thought, 'Put the cables down the center of the cam,' but in the next instant, I figured, 'Well, that's too easy.' Then I thought of adding two parallel string tracks, and have them meet together. In the end I didn't think we would be able to clear the string track. So I kind of [shelved] the concept. But I had enough guts to tell [brother and G5 CEO] Matt [Grace], and [G5 President and father] Lou [Grace]. They said, 'That's just too simple of a solution.' So we kind of sat on it a bit. And then we came back to it and said, 'Yes, there's something to it.' In the end I guess [the injury] was a blessing in disguise."

As Nate and company further developed the concept, the findings were more than impressive. Especially when combined with a flexing cableguard system that G5 had developed years previously, patented back in 2008, and had more or less shelved waiting for the right moment. When the new cam system came along, they knew the time was right to bring the new technologies together. That design, the Ti-Glide cableguard, makes use of a flexing titanium rod—and also incorporates a similar cableguard system seen on some 2010 Quest bows. The new design allows the cables to move toward the arrow as the bow is drawn, minimizing the "side load" on the limbs.

The final Prime prototype found the entire system reduced standard cam lean by an astounding 90 percent—or more. It also drastically improved nock travel in both vertical and horizontal planes, delivered more-consistent left and right impacts, and was much easier to paper tune. It also delivered yet another instantly recognizable benefit: Once the bow was rigged and tuned, the sight pins were directly inline with the arrow and string—a phenomenon with real benefits. The bow was faster and easier to set up and tune, delivered better long-range accuracy, with more-consistent, more-reliable limbs.

"When you combine [the Ti-Glide] with those parallel-track cams, what you get is a very consistent forgiving bow, and it's shooting very, very nicely," Grace said. "The bow is completely consistent from draw to finish. You will have straight, horizontal nock travel. And the load is balanced, so the limbs aren't twisting.

"What we've found is that when you remove cam lean, the limbs don't twist, the limbs last longer, the riser is stiffer, and it's more 'dead in the hand.' So it's really affecting everything."

Two premium Prime bows are currently available: the Centroid, a 34-inch axle-to-axle model with 7.25-inch brace height that delivers speeds of 330 fps plus; and Shift, a 30-inch model offering the same brace height and speed. Both bows feature premium forged 7000 series machined aluminum alloy risers, and premium Gore fiber string and cables. Expected retail is $1,000. Before delivery each bow will be drawn 100 times on an automated cycle machine before being timed and super-tuned. Speed, draw weight, and draw length will be recorded and printed on a certified card that accompanies each bow.

For more info call (866) 456-8836, log onto the G5 Prime website.

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