“Gladiator” Buell XBRR-Powered Street Tracker

Buell Street Tracker

Hot-Dock Custom Cycles builds a 150-hp street tracker…

Introduced in 2006, the Buell XBRR was a factory-built, turn-key racebike intended to give buyers a one-way ticket to closed course road racing. The monster 1339cc Thunderstorm V-twin at the heart of the machine was based on the traditional Harley-Davidson Sportster engine, though it was de-stroked, bored to just under 1350cc, and featured dual-downdraft 62mm throttle bodies–the largest on any production motorcycle!

Buell Street Tracker

Output was said to be 150 horsepower at 8000 rpm and 100 pound-feet of torque at 6400 rpm — Ducati 999R territory! As you might imagine, this powerplant made quite the impression on test riders:

“It doesn’t have a powerband per se; it just explodes off idle and runs smack into its 8200-rpm rev limiter. If the power delivery resembles anything, it’s a 500cc two-stroke motocrosser’s; no matter how little gas you give it, you’re accelerating hard, the rear tire scrambling to keep up. This was a bit of an issue exiting Buttonwillow’s tight and slippery Turn Two, where the XBRR’s rear tire stepped out no matter how gingerly I turned the throttle.” —Motorcyclist

Recently, we got in touch with Keiji Kawakita of Tokyo’s Hot-Dock Custom Cycles, who has more than half a century of riding history under his belt.  He’s made a name for himself worldwide building V-twin customs since his shop opened in the mid-1980s. When “Gladiator” turned up on his personal social media account, we had to know more.

Buell Street Tracker

Keiji purchased a 2007 Buell XBRR engine with 0 miles on the clock and decided to build a street tracker around it — not a customer project, but a bike just for his own enjoyment. The frame is completely custom, a one-off unit that Keiji built from 4130 steel, with a Ducati swingarm mounted upside down from normal!

Buell Street Tracker

As you can imagine, there were a number of challenges in putting this race-spec fire-breather of an engine into a street bike: charging system, ignition, EFI mapping, and more. However, the result was certainly worth the effort. This is one of the baddest street trackers we’ve ever seen, period, and Keiji says the riding experience can be summed up in a single word:


Below, Keiji gives us a few more details on the “Gladiator.”

Buell XBRR Street Tracker: Builder Interview

Buell Street Tracker

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

Hot-Dock Custom Cycles, since 1984, based in Tokyo, Japan. I’m Keiji-Kawakita, born 1954. Age 66, 55 years of riding history.

• What’s the make, model, and year of the donor bike?

Buell XBRR, 2007. New engine with 0km. Purchased as engine only.

Buell Street Tracker

• Why was this bike built?

I built it just for myself to ride, because the engine was so attractive.

Buell Street Tracker

• What was the design concept and what influenced the build?

Flat track racing. A street bike like the Indian FTR.

Buell Street Tracker

• What custom work was done to the bike?

Frame is 4130 steel made by myself, swingarm adopts a Ducati rear wheel. The rest is the same mechanisms as the rubber-mounted Buell.

Buell Street Tracker

• Does the bike have a nickname?


Buell Street Tracker

• Can you tell us what it’s like to ride this bike?


Buell Street Tracker

• Was there anything done during this build that you are particularly proud of?

Riding a racing engine on the street, there were many obstacles to overcome, such as the charging system, low compression, ignition device, EFI, etc.

Buell Street Tracker

Follow the Builder

Website: www.hot-dock.co.jp
Facebook: @Hot-Dock-156289354531582
Instagram: @keijikawakita


  1. Martyn Carl Woodhead

    This things just short of tracks?

  2. A real eye-catcher that’s almost comical. Kinda gob-smacked and not sure what to say….

  3. XBRR engine is mui bonito and super cool. Envying that. But there are so many seemingly unnecessary compromises to ‘tracker’ shapes and lines (which exist as they normally are for very specific performance based reasons) that this finished design just looks like the builder didn’t know any of that. And the worst thing in the world is building something you don’t understand.

Leave a Comment

Your email address will not be published. Required fields are marked *