Evolution Industries’ Sportster Open-Primary Beltdrive System: Get Evol

The Evolution Industries Sportster open-primary kit comes complete with everything you see here. The kit is not only complete, but it looks awesome, too.

First things first; any time you work on a bike, disconnect the battery. Next, Anthony drained the primary fluid, removed the shift linkage, and took the adjustment out of the clutch cable. Then he removed the derby cover, followed by the shift-arm shaft. At this point he was able to unbolt and remove the primary cover and gasket.

With the derby cover removed, the clutch-release mechanism was taken off with a small flathead screwdriver. The snap ring on the clutch assembly came off next, followed by the adjuster screw plate, which allowed access to the clutch hub nut.

Next, the engine sprocket was removed, along with the clutch assembly and primary chain. The eight bolts securing the sprocket to the rotor were then removed so the sprocket could be pressed out of the rotor (the rotor will be reused later).

Here are the parts that will be reused for the new beltdrive: rotor, clutch adjustment screw, retaining ring, clutch inner and outer ramp, three bearings (not shown), coupling, nut, locking plate, spring, and washer.

After cleaning the primary area with contact cleaner, it was time to start the install of the new Evol 3-inch beltdrive unit.

To get started, the six bolts on the clutch plate had to be removed, along with the clutch plates themselves (be sure to note the order of the discs when removing them).

Once the new primary gasket was in place, Anthony installed the primary (along with the front and rear pulley) to check for proper alignment. To check the alignment of the pulleys, Anthony used a metal straightedge covered with painter’s tape to protect the new drive. The alignment was pretty close, but it required a .065-inch spacer on the front pulley to make it perfect.

With the alignment dialed in, the primary came off. Then the rotor was bolted to the front pulley using the eight bolts supplied in Evolution’s kit.

Next, the primary was installed for the final time and tightened to factory specs.

Then, with the drain plug installed, the primary was filled. The stock setup takes up to 32 oz. of fluid, but because of the new beltdrive system, 8 oz. (about the size of a standard Red Bull can) was all that was needed.

The belt was next. However, the pulley shoulder plates had to come off first. Then the belt was slid in place, and the shoulder plates were bolted back on. (The belt slack should be 1/4-inch to 1/2-inch up and down).

Next, Anthony installed the clutch plates, starting with the thickest steel plate and ending with the friction plate.

The adjustment screw was installed into the pressure plate, along with the retaining ring.

Anthony then installed the pressure plate and clutch springs.

The primary cover was next. The chrome cover really adds a mechanical look to the beltdrive.

The cover and two belt guards were installed using the stock bolts and blue threadlocker.

Next, the clutch cable was installed, along with the coupler, bearing, clutch adjuster nut, and the lock-plate spring.

To keep shift-linkage curvature to a minimum, a 1-1/2-inch spacer (not included in the kit) was used between the shift arm and the front of the linkage.

Here’s a comparison between the stock primary and the new 3-inch beltdrive (above, and above right). As you can see, it’s an incredible difference and gives the Sporty the open-belt look that’s popular with all the Big Twins. You’d be hard-pressed to find a more innovative and impressive kit anywhere.

When we first heard a rumor about a 3-inch open beltdrive system being developed for the Sportster, we were very excited to see what the finished product would look like, and of course to see one installed. Naturally, all of our friends who ride Sportsters were waiting on pins and needles to get the inside scoop on when this kit would be made available to the public. They didn’t have long to wait.

Well, rumor became reality at the last V-Twin Expo in Cincinnati, OH, as Evolution Industries unveiled its 3-inch beltdrive kit for the Sportster. The response to the system was phenomenal. After talking to the people from Evolution Industries about what went into the creation of this beltdrive system, we knew right then and there that we had to get our hands on one and do the install. They were more than kind enough to oblige.

As luck would have it, our friends from LifeStyle Cycles in Anaheim, CA, were working on a custom ’03 Sportster project that was a perfect candidate for the Evolution Industries beltdrive. The ’03 Sporty already had a stretched tank and custom paint and pipes, and would really look sharp with an open primary. We got the kit down to LifeStyle Cycles and followed along as mechanic Anthony Walton did the expert install on this innovative and unique beltdrive system. During the installation process, LifeStyle Cycles found a couple of ways to improve on this already incredible setup, so you get to see them here first. But enough talking-let’s dive right in to the installation process of this beltdrive system.

With the derby cover in place, the installation took an interesting turn when LifeStyle Cycles’ owner Junior decided he wanted to extend the left foot control out 1 inch. This extension will give the controls better ergonomics, help strengthen the shift-rod connection from the shifter, and take stress off the connection to the shift arm to the shift linkage. So Anthony removed the left side control. To accommodate the extra 1-inch spacers, new bolts were acquired that were 1-inch longer than stock. With a four-point connection, there’s no worry about lack of strength on the controls.


Evolution Industries
(909) 594-7969