How to build a Harley Sportster street tracker, the Mule way

Custom Harley Sportster street tracker by Mule Motorcycles
Like most skilled craftsmen, Richard ‘Mule’ Pollock can turn his hand to myriad custom motorcycle build styles. But there’s one particular type of bike that sits closest to the center of his wheelhouse; the street tracker.

Mule has extensive experience building and racing flat track bikes, and he knows just how to repackage them for street use. So if you’re looking for a Harley Sportster street tracker with a nostalgic American flat track racing vibe, specced for spirited road use, he’ll deliver it with his eyes closed.

Custom Harley Sportster street tracker by Mule Motorcycles
That was pretty much the brief for Mule’s latest project—with a few special considerations added to the mix. “The customer wanted a Mule-style street tracker with a motor that wasn’t too wacky or high-strung,” the Idaho-based one-man band tells us. “Great for everyday riding, and with the Harley XR750 orange and black paint scheme.”

Other requests were gold billet wheels and front forks from an MV Agusta F4. From there, Mule was free to execute his motto; “Every single part gets the attention it deserves, which is a lot.”

Custom Harley Sportster street tracker by Mule Motorcycles
The donor was a 1991-model Harley-Davidson Sportster 1200. It’s a vintage that Mule favors, because the earlier Sportsters have much lighter frames than the newer rubber-mount variants. (It’s more or less a 4.5-kilo [10-pound] weight saving, straight out the crate.)

Even though the bike had been featured in a magazine previously, the motor was in a less-than-desirable condition. So Mule tore it down to its nuts and bolts, and rebuilt it from the ground up with his go-to engine mods.

Custom Harley Sportster street tracker by Mule Motorcycles
“This would be new rods and lower-end bearings, with balancing by Dark Horse Crankworks in Milwaukee,” Mule tells us. “The top-end got my standard treatment, with porting, big valves, and proprietary pistons from Branch & O’Keefe. The cams came from Andrews.”

“The stock CV carb was retained with detailed upgrades by Randy Troy’s Carb Restorations. My friend Chuck Connell and I built the exhaust with tubing and a megaphone muffler supplied by Cone Engineering. A ForceWinder intake and K&N filter finish off the air entry, and an RSD one-piece Rocker box cover replaces the stockers.”

Custom Harley Sportster street tracker by Mule Motorcycles
The chassis mods are also typical Mule fare. He shortened and looped the tail, fabricated an electronics tray (which hosts a Shorai Lithium-ion battery), and installed new exhaust mount bungs. There’s also a new side stand mount with a Mule chromoly side stand fitted.

Other changes include new tank and seat mounts, and adjustable fork stops. Mule also moved the lower shock mounts six inches forward and wedged in a set of adjustable K-Tech shocks.

Custom Harley Sportster street tracker by Mule Motorcycles
Next up, Mule saw to his client’s specific requests. 58 mm Showa MV Agusta forks were fitted via oversized yokes, spread wide to accommodate Dunlop DT4 road-legal tracker tires. 19” CNC-machined flat track race wheels from Lowery Racing ticked the final box.

The Sportster’s new braking setup is the stuff of dreams. Twin front Braketech discs sit on custom carriers, gripped by six-piston Nissin calipers from the same MV Agusta as the forks. They’re controlled by a Brembo master cylinder off a Ducati, via Crown Performance brake lines that flow through a custom splitter mounted to the front of the lower yoke.

Custom Harley Sportster street tracker by Mule Motorcycles
Mule picked a Beringer caliper and a KTM master cylinder for the rear brake. The CNC-machined right-hand-side foot control mounting plate is a ‘standard’ Mule part. Classic Bates rubber pegs poke out from either side of the Harley.

Up top you’ll find an LED headlight, tiny LED turn signals, and a Trail Tech gauge. The stainless steel handlebars are Mule items, fitted with a Motion Pro throttle and cables, a Buell clutch lever, and Renthal grips.

Custom Harley Sportster street tracker by Mule Motorcycles
For the bodywork, Mule paired a classic XR750-style tank with a flat track tail from First Klass Glass, topped with a Saddlemen seat pad. Lurking underneath the seat is a Mooneyes oil tank, modified for more capacity.

SBK Paint handled the livery; a classic H-D racing orange-with-black affair. The Barnett Harley-Davidson sponsor graphics might seem out of place, but there’s a story behind them.

Custom Harley Sportster street tracker by Mule Motorcycles
“They were a long-time racing sponsor of Mearl Barnett (no relation) and myself in our Hooligan series exploits,” says Mule. “I had one spare set of tank graphics and the customer really liked them, plus they honor the XR750 race tradition.”

As always, Mule has delivered a Sportster street tracker that sacrifices neither function nor form—tipping its hat to the track while tearing up the streets.

Mule Motorcycles | Instagram | Images by Olivier de Vaulx

Custom Harley Sportster street tracker by Mule Motorcycles

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