Installing a Barnett Scorpion 3-Inch Belt Drive
January 24, 2006
Filed under Motorcycle Features: Bikes, Blokes, Culture and Beyond
by Scott Dalgleish
photography by John Hyder
The great thing about installing a belt primary drive is that it takes about the same time and effort as installing an OE chain drive. So if you’re interested in adding the look that sets the bike apart from the oil-bathed chain-driven stock Harley, it’s worth considering. There is something about having that rotating mass out in the open for the world to see. Maybe it adds an element of danger making the rider appear more like the outlaw type, or maybe it’s the clean, simple engineering. Whatever it is, belt drives have an unusually attractive appeal.
One of the latest entries to the Harley belt-drive market is from Barnett. You probably recognize the name. For years, Barnett has been considered one of the industry’s leaders in performance clutches. So it is only natural for a top aftermarket clutch manufacturer to round out its line with a belt drive and performance dry clutch combination.
The open primary (belt drive is not a form of elections) was an important element in the look and style of the American Rider No School Bobber. We welcomed the opportunity to incorporate Barnett’s all-new Scorpion 3-inch belt drive into our project, complete with the new Barnett Scorpion clutch. The assembly includes a belt guard. Speaking of the belt guard, if you are contemplating installing an open primary, having a protective belt guard should be at the top of your list of components. If your custom is intended to be a rider as opposed to a trailer queen, then a guard for the open primary is a must.
Components are CNC machined from 6061-T6 billet aluminum and polished to a show-quality finish. The Scorpion lock-up clutch assembly can be used in wet or dry primaries and offers the ultimate street or strip performance, according to Barnett. The Scorpion’s clutch provides a 100 percent increase in surface engagement area when compared to the stock Harley clutch. Barnett’s use of lighter coil springs in combination with adjustable pressure arms progressively increases pressure to the clutch spring as engine revolutions are increased. The use of the lighter springs results in less effort at the clutch lever. Barnett also includes extra sets of springs to offer greater flexibility in tuning the Scorpion’s tension to match your engine’s performance. This setup should offer us the versatility we are looking for when teaming our Branch Flowmetrics No. 4 95-inch Twin Cam to the transmission.
The Barnett Scorpion Belt Drive comes fully assembled. This proves to be a double-edged sword. On one side we were able to have a first-hand visual of the completed assembly. The other side required us to take the time to disassemble everything to install the unit. That being said, the installation proved to be straightforward. No special alignment tools or procedures are necessary. Drain the primary oil, remove the outer primary cover, remove the primary chain, drive sprockets and clutch assembly, starter and inner primary cover. Installation of the Scorpion’s parts went according to the instructions supplied by Barnett, right down to the cool-looking belt guard.
In just a little over two hours, the installation was completed and our bobber project bike took on a look of its own. The Barnett Scorpion belt drive could easily be considered a do-it-yourselfer’s project. And few projects will have more impact on a bike’s styling and individuality.
The team at County Line Cycles performed the installation along with the rest of the assembly of our project bike. Barnett’s part number 38590 fits 1990 through 2005 Harley-Davidson Softails. After we get some miles on the bike we’ll report on its performance in a future issue.
Product: 3-inch belt primary drive Price: $3,745 Supplier: Barnett Tool & Engineering; 805-642-9425; www.barnettclutches.com
Special thanks to County Line Cycles, 185 E. Easy Street Unit G, Simi Valley, CA 93065; 805-578-8830; www.wefixharleys.com.