Peer Review Analysis by Blacky Swartz
By R. Blacky Schwarz
Centaur Archery, 104 Highland Drive, Corvallis, MT 59828
Model: Carbon Elite Longbow
Length: 60 inches
Draw Weight: 51 pounds at 28 inches
Brace Height: the recommended brace height is 7 inches and is measured from the string to the first lamination on the belly side of the limb.
Physical Weight: 21 ounces
Draw weight: 51 pounds at 28 inches
Stored energy: 45,61 foot-pounds
Stored energy per pound of draw weight: 0,9 foot-pounds per pound
Arrow weight: 457 grains
Arrow speed: 195 fps with mechanical release
Kinetic energy: 38,6 foot-pounds
Dynamic efficiency: 84.6 per cent (kinetic energy/stored energy)
Arrow Speed: 190 fps with finger release
Length: from fade-out to fade-out, the riser measures 161/2 inches in length
Shape: slightly deflexed
Sight Window: the radiused sight window measures almost three inches in height
Centre Cut: cut to centre
Material: the centre part of the riser, which features the fade-out ends, is cut and ground from charcoal silvertone Dymondwood and then embedded between the limb laminations. Dymondwood of the same colour is glued to the belly side of the limbs to form the grip part of the riser. For looks and contrast, a thin accent stripe from red micarta is placed between the outer limb lamination and the grip part. The shelf is designed with a downward slope towards the sight window, which helps to keep the arrow on the Velcro rest during hunting situations. Shelf and sight window are radiused to keep the arrow contact areas to a minimum. Artistic engraving work on the palm side of the grip, depicting a knapped arrow head, shows the craftsmanship that goes into building the Centaur bows. Little dimples cut into the surface of the grip not only prevent slipping of the bowhand, but also enhance the optical appearance of the bow. Jim calls this eye-catching engraving “stippling” and offers it as an option on his bows. An overlay from red micarta and black glass, that matches the overlays on the limb tips, is glued to the back side of the bow. For a perfect fit, finger grooves are cut into the front of the riser according to a tracing of the customer’s hand.
Medium-low pistol-type grip with finger grooves.
Shape: reflexed limbs with a trapezoid cross-section that is wider at the belly side.
Limb width: the limbs measure 11/4 inches at the fade-outs and taper down to five eighths of an inch just below the string groove.
Material: two tapered layers of ActionBoo on the back side of the bow and a parallel layer of Maple ActionWood on the belly side are used for the construction of the limb core. The lamination on the back of the bow is Jim’s own lay-up from carbon fibres. There is a woven matrix on the surface for protection and to provide a sophisticated look. A specially-engineered hybrid lamination, designed to withstand high compression forces, covers the belly side. All limb laminations run continuously from tip to tip.
Tip overlays: red micarta with a top layer of black multi-directional fibreglass is the material of choice for the limb-tip reinforcing overlays, that permit the use of modern, low-stretch string materials. The size and shape of the limb tips shows Jim’s attention to details. Cutting the tips to a length of merely half an inch, measured from the outer edge to the string groove, results in a higher dynamic efficiency, since a lower mass has to be moved during the shot.
For moisture protection the bow is sprayed with five coats of Thunderbird two-part epoxy, which also provide a non-reflective surface, suitable for hunting.
Dynaflight 97 string material is used to build the Flemish twist string with padded loops, that is supplied with the bow. Strings made from other low-stretch, high performance materials like D-75, BCY 452-X, TS-1, BCY 8125, Fast Flight etc. can also be used, without any ill effects.
The Centaur longbows can be ordered in bow lengths of 54, 56, 58, 60 and 62 inches and in a right-hand or a left-hand version. The reviewed Carbon Elite is the performance-enhanced, top-of-the-line model with the specially-engineered outer laminations. There are different combinations of riser woods to choose from for this model. Jim also offers other models with veneers under clear glass and a multitude of different wood choices for the limbs and risers. All Centaur bows can be ordered in a two-piece take-down version and with options like Pierce-Points, custom engraving or inlays to personalise your bow. The grip can be made in different heights and is sculptured according to a hand tracing, that the customer supplies on a piece of paper. For all available options please refer to the website.
A force-draw curve was obtained from the reviewed bow using a digital force gauge with a resolution of 0,1 pounds. Measured bow weight was rounded to the next half pound. The different arrow speeds were achieved with the bow shot from a shooting machine with a mechanical release and with finger release, using a “Crick-It” clicker and a deerskin glove. The string was pulled to 28 inches A.M.O. which is 26 1/4 inches from the string to the deepest point of the grip. The three arrows for the speed testing had a weight of 9 grains per pound of measured (not stated) draw weight. A 16-strand Fast-Flight string without any attachments (silencers, etc.) was used. Speed measurements were taken three feet in front of the back of the bow with two chronographs set up in a tandem configuration. Each arrow was shot a minimum of six times and overall achieved speeds were rounded to the next whole digit.