A Japanese-built Sportster inspired by American Flat Track racing…
Since its introduction in 1957, the Harley-Davidson Sportster has become and remained one of the motorcycling world’s most popular platforms for customization. Sportsters have been chopped, bobbed, transformed into cafe racers and scramblers, raced on road circuits, competed in the Baja 1000, and more.
Today, the rise of Super Hooligan flat track racing has put the Sportster back in the limelight. The series has been called “a beautiful mashup of custom bike building, flat-track, and outlaw street racing” where machines of 750cc / 400 pounds and above compete in grassroots-style racing:
“It harkens back to a time when any American could strip down a streetbike in the barn or a backyard shed, ride it to the track, race at a local track, and, if fortunate, ride it home again.” –Thunder Press
Enter our new friend Katsu, a former race engineer who spent ten years working on four-wheeled racers, eleven years customizing Lamborghinis and other exotics, and the last eight years building custom Harley-Davidsons and other two-wheeled machines out of his shop BelAir Custom — located in Kanagawa, Japan. Says Katsu of his nation’s Sportster scene:
“In Japan, most of the Sportster customizations are Frisco style, and there are few flat tracker style customizations. However, I really like the flat tracker style and the owner agreed with my suggestion, so I built this bike.”
And what a bike it is. Inspired by American flat track racing, Katsu has transformed this 2001 XL883 into one of the raddest Sportster street trackers we’ve seen, featuring WP inverted forks from a KTM, upgraded brakes at both ends, Borrani 19-inch wheels with flat track rubber, and a custom stainless steel exhaust with undertail exits — something we’ve never seen on one of these Sportster builds! The result is known as the “XR39”:
“I named it XR to mean a dirt tracker that can also ride on the street. ’39’ is the owner’s lucky number.”
A lucky owner indeed! Below, we get the full details on this stunning street tracker.
XL883 Street Tracker: Builder Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
The BelAir Custom workshop is located in Kanagawa, Japan. I was a four-wheeled race engineer for 10 years and then spent 11 years customizing Lamborghinis and other exotic cars. After that, I’ve been doing custom builds for Harley-Davidson and others for 8 years.
• What’s the make, model, and year of the bike?
2001 Harley-Davidson XL883.
• Why was this bike built?
In Japan, most of the Sportster customizations are FRISCO style, and there are few flat tracker style customizations. However, I really like the flat tracker style and the owner agreed with my suggestion, so I built this bike.
• What was the design concept and what influenced the build?
I was influenced in my design concept and construction by American flat track racing.
• What custom work was done to the bike?
The front end is from a KTM Duke 390, with WP inverted forks. KTM brake calipers are used and the brake rotors are large diameter Harley-Davidson ones.
For the rear brakes, Yamaha YZF monoblock calipers were installed.
Custom-made aluminum oil tank, relocated to the left side, and out back custom SUS exhaust with hand-formed side cover.
Custom-made turn signal switches and engine starter switches.
A small lithium battery made by Shorai has been installed under the seat.
For the rear suspension, 360mm dampers made by Nitron were installed. Borrani 19-inch wheels front and rear, Dunlop front tire and Shinko dirt track tire for the rear.
The intake manifold was custom-made and a Dell’Orto PHM 40mm carburetor was installed.
• Does the bike have a nickname?
I named it XR to mean a dirt tracker that can also ride on the street. “39” is the owner’s lucky number.
• Can you tell us what it’s like to ride this bike?
The inverted fork front end and Nitron rear suspension make the bike very easy to control and very comfortable to ride. The gear ratios can be changed for both city and highway riding.
• Was there anything done during this build that you are particularly proud of?
Very few custom Harley-Davidson or Sportster bikes have exhausts out of the back, so it’s very eye-catching.
Follow the Builder
I like it! And I’m also very impressed Katsu stuck a muffler under the seat there instead of running straight pipes like every other builder, very good!
You know what I just realized about Japanese art? It combines exquisite craftsmanship and attention to detail with a real sense of humility and scale. Respect for a beautiful bike.
You’re absolutely right, Gabe. Having studied traditional Japanese aesthetics as part of my graduate thesis, I completely agree, and I see these same qualities in the work of many Japanese custom bike builders. It’s exactly why I’m such a fan of Heiwa, Shinya Kimura, and many others.
What you guys don’t get is , it’s not a factory bike, so as nice as I think it is, the builder could make it any way he wanted. The outcome is puss, but do not expect those details from a factory bike….
Nice work but is that chain as tight as it looks?