Bow Review: Prime Inline 3

Take accuracy and shootability to another level!

April 07, 2022 By Jon E. Silks

It's the beginning of a new era at Prime — an era of centricity, alignment and accuracy achieved through a single-body cam.

With the introduction of Prime’s new Inline flagship bow series, we see a bold move forward with a new power system designed to achieve all the benefits of the company’s Parallel Cams and beyond. The series includes three models — the 1, 3 and 5 — with those numbers correlating to the axle-to-axle length past 30 inches (31, 33 and 35 inches).

Now, let’s take a closer look at the Inline 3.

New Cam System

Prime made a decision to add a new platform design to its popular bow lineup with the intent of not only maintaining, but also improving on the performance found in its Parallel Cam designs while also simplifying the entire operation. The new Inline Cam System is similar to a three-track binary cam, utilizing a string, power cable and take-up cable, all anchored exclusively to the cams. The difference is in how Prime manages the increased forces on the cables, specifically the take-up cable, during the draw cycle and at full draw.

Using the cable grooves, Prime shifts the take-up cable over the top of the axle’s center — basically centrally aligning the string and cable to focus the lion’s share of the force on the centerline. As you might expect, this balances the load on the system to reduce efficiency-robbing cam lean. The Flexis AR cable-management system plays a critical role in this design as it uses a flexible arm to allow the rollers and cables to move toward the centerline of the bow and back again during the draw and shot cycles.

A rotating module on the machined aluminum Inline Cam adjusts draw lengths between 26 and 30.5 inches, in half-inch increments, with only two small screws (another significant simplification over the Parallel Cam system). Clear engraving/stamp marks on the module and main cam body ensure accurate adjustments. A series of different-sized spacers, included with your purchase, can be arranged on the axles to actually move the cams side to side in order to correct for left/right paper tears. Prime also moved to a single limb stop to produce a super solid back wall.

Curves of Consequence

Prime’s popular Swerve Riser technology is hard at work on the Inline 3, bringing harmony to the top and bottom sections of the riser. Swerve, which is a structural feature on the bottom half of the riser designed to mimic the sight window structure in terms of movement and flex, controls lateral movement of the cams during the draw and shot cycles. The bottom line is that less movement equals more consistency — to prove their design, Prime physically measured and found lateral cam movement was reduced by 50 percent.

Another riser feature, this one from the company’s Project Centergy, is designed to bring superior balance and rock-solid aiming qualities by running the center of the overall rig through the throat of the grip rather than the nocking point. You’ll notice the top cam is larger to compensate for the offset nocking point. The Inline 3 riser is first forged and then machined from a block of a proprietary blend of 82X aluminum. To see the 15-plus riser finish options, visit g5prime.com.

Prime’s Nano Grip found instant popularity on the company’s Nexus Series and is back on the Inline rigs. The Nano uses NASA-developed Aerogel, which serves as a buffer between the riser and plastic overmold grip, blocking the cold temperature of the metal from transferring into the grip. This allows the use of lighter gloves — or even no gloves — in colder weather, which for many translates into better shooting. The contoured and textured Nano Grip is also designed to produce a neutral wrist position.

The Flexis AR feature joins a flexible mounting arm and a set of rollers to not only contain the cables but also control them during the draw and shot cycles as well. During the draw cycle the arm bends toward the bow’s centerline and then quickly moves back and out of the way of vanes at the shot. The mounting arm load can be adjusted for fine-tuning arrow flight.

A string stop and new set of dampeners located at the bottom of the riser near the limb pocket work to reduce vibration and shot noise, while a metal stabilizer-mounting insert takes the hassle out of repeated stabilizer attachment.

Shifted Limbs and Cups

A close look at the machined aluminum limb pockets shows a position just off center. This configuration works with the new Inline Cam System to shift the cables toward center while also maintaining the 7⁄8-inch center shot that customers have come to rely on when setting up their rigs. The pocket supports and controls each individual limb on all sides and ensures precision at the critical riser-to-limb interface. Prime outfits its Inline 3 with short and stout limbs that are set far apart to enhance stability through torsional rigidity. Limbs are available in peak draw weights of 40, 50, 60, 65, 70 and 80 pounds.