May 26, 2021
Trends are common in the archery world. They are driven by manufacturers who respond to consumer demands, advancements in new technology, or a change of direction when the limits of existing technology or physics are reached. Often it is a combination of the two.
Some recent trends in crossbows involve speed and size. In this case, the challenge increases one while reducing the other; not an easy task, as the two tend to be inversely correlated. The easiest way to increase speed is to increase power stroke and limb length. Consumers, however, have made it clear that they want more compact crossbows, and the industry has gone to great lengths to make the bows shorter and narrower while increasing speeds. Neither trend is new; they have just been highlighted more recently.
The rise of compact crossbows
The first noticeable shrinkage came, somewhat unintentionally, with the introduction of Scorpyd’s inverted limb technology. In addition to better balance and a quieter, smoother shot, the stock model boasted an axle-to-axle width of 16 inches, up from an average of around 22 inches at the time. One of the first front arches with noticeable narrowing was TenPoint’s Vapor, 17½ inches wide at rest but a meager 123⁄5 inches when cocked. Others like Carbon Express, Barnett, Bear and Killer Instinct have followed suit. Excalibur has even managed to refine the recurves with its Micro series.
The next step came from Ravin – the company’s HeliCoil technology helped it create an ultra-compact 6-inch width. Other arcs like CenterPoint and Horton were down in the teens, with the rest of the pack at 20 inches or less. The subcompacts had arrived and the field was filled the following year with examples such as Mission’s 10-inch-wide SUB-1 and TenPoint’s 6-inch-wide Stealth.
Increase bolt speed
In 2011, the average speed of the new crossbows was around 330 fps, with some exceptional “speed” arcs from Scorpyd, Stryker and Inferno in the 375-385 fps range. Five years later, the average was around 360 fps, but the field was full of arcs in the 300 fps, with models from Barnett, Darton, Excalibur, Scorpyd and TenPoint at 400 fps or more. In 2020, crossbow makers were making 400 fps almost a standard – Ravin’s R29X boasted 450 fps, topped with TenPoint’s Vapor RS470 at 470 fps – and they did so without sacrificing a smaller size.
While similar technology existed at the time, Scorpyd’s Jim Kempf was the first to introduce reverse limb technology to this side of the pond. This, combined with a system where the rope passes behind the riser and in front of the cam, maximizes a shorter power stroke rather than using a longer one to produce more speed. The end result was, until recently, a record breaking 480 fps over a 13 inch width.
TenPoint’s Narrow Crossbow (NXT) technology arc assembly utilizes several physical advantages. A fully rotating cam system takes full advantage of the eccentrics. The extra strong Dual Flex limbs are mounted in a Tri-Lock pocket system for increased structural strength. Then, the Vector Quad Cable system runs cables from a riser mount through turnbuckles on either side of the barrel to the grooves around the cam pins, instead of running them under the barrel. This helped TenPoint achieve 400 fps at less than 6 inches wide. This year’s models combine NXT with a reverse limb setup for 470 fps at 6½ inches wide.
Ravin caused a sensation by launching its HeliCoil technology on the market. As the name suggests, it winds the cables away from the top and bottom of the cams in helical grooves. This allows for 340 degree rotation while keeping the cams level and balanced. The frictionless flight system also allows the rope and breech to float above the rail, achieving a speed of 450 fps for a crossbow only 6 inches wide.
Barnett took a slightly different approach, borrowing another recent trend from the compound side. Its Hyperflite series crossbows use a proprietary .204 micro-diameter Hyperflite bolt. The bolt’s 21% increase in FOC and its 61% higher ballistic coefficient reduce wind drift, increase the accuracy of the descending range, and allegedly increase penetration by up to 22%.
Crossbows are also getting shorter and shorter, which is also not an easy task given the importance of power stroke. The average length in 2011 was 3 feet. Today it is somewhere between 3 and 6 inches shorter, depending on the arch. The stirrup is an important factor in the overall length. Barnett solved this problem by incorporating it into a riser, effectively eliminating 6 inches or more of length. Darton was among the first to incorporate a shorter bullpup style stock, followed shortly thereafter by Carbon Express, Stryker, and a subsequent series of tactical stock arcs. Along with this, it was possible to move the locking mechanism well back, in extreme cases such as the Ravin R25 and Darton Toxin series, to the back of the stock. These innovations, along with the aforementioned technical advancements, allowed for a shorter overall length without reducing the power stroke.
Where and when will it end? Earlier this year, Ravin announced its new R500 series capable of throwing 400-grain bolts at 500 fps thanks to the company’s proprietary HexCoil camera system. What’s even more impressive is that the arches feature a compact frame, measuring 28 inches long and just over 3.6 inches wide axle-to-axle when cocked.
Some engineers say we are approaching the physical limits to make faster arcs while ensuring safety and reliability. There is still room for width reduction, but even that circumvents the law of diminishing returns. A better question might be: what’s the next big trend? Time will tell us.
Tip of the month
Changing the magnification on an adjustable scope changes the relative distance between reticles or points. Newer scopes designed for fast arcs are typically calibrated for speed rather than power on the dial. If not, you can “tune” the accuracy downstream with practice on the range. First, aim in your reticle or higher point for 20 yards. Then dial your 40 yard reticle – usually the third from the top – at 40 yards. The other distances should now be fine, but it is better to go back and check 20 yards and confirm longer distances.