Sorbo’s Thunderbike: Honda Dominator 650 Flat Tracker

From Fuchs Workshop: Niko Sorbo’s Honda Thunderbike, “Rusinella”…  

More than two decades ago, Massimo Rinchiuso of Italy’s Fuchs Workshop began preparing track bikes. Today, his Ravenna-based workshop specializes in hand-shaped aluminum bodywork, 3D design, CNC parts, full-blown custom builds, and the preparation of vintage flat trackers like the early 90s Honda NX650 you see here. 

This Dominator 650 is a particularly special project, as it was built for professional flat track racer Niko Sorbo, whose accomplishments speak for themselves: three titles in the French FFM Championship, one title and a second-place cup in Germany’s Krowdrace series, an Italian FMI Cup, and more. 
But Niko’s off-track pursuits shine just as bright. He’s a beloved figure in the European flat track community, and he’s helped bring the sport home to Italy:

“With the Dust & Fun project, a trophy designed to bring new riders closer to the discipline, he has played a decisive role in the creation of a true Italian flat track scene.” -Massimo, Fuchs Workshop

Believe it or not, this Fuchs-built Honda Dominator 650, designed for the Thunderbike class, was the flat tracker that started it all for Niko. Thunderbikes are typically 500-750cc air-cooled framers (custom-framed trackers) or modified street bikes. The important personal nature of this race bike is evident in the nickname Niko’s bestowed on the #48 Dominator:

“This Dominator has become a personal symbol for Niko, so much so that he named it after his mother’s nickname: Rusinella.”

Massimo completed reworked the chassis geometry — lowering the subframe, altering the steering angle, and installing a longer swingarm — so the bike is basically a framer. Meanwhile, master engine builder Claudio Lanconelli built the RFVC engine into a high-compression unit that produces ~60 horsepower — quite stout for a bike that weighs just 225 pounds dry!

Those are just the start of the modifications that transformed this aging trailie into the fire-breathing Thunderbike you see here. Below, Massimo himself gives us the full story of the build, with more backstory and technical details. 

Stay tuned for more flat trackers from Fuchs Workshop!

#48 Thunderbike: In the Builder’s Words…  

The motorcycle presented here is a pure flat track machine, based on the Honda NX650 Dominator, an iconic model that marked Niko Sorbo’s entry into the world of oval racing. It was on this very bike that the Italian rider took his first steps in the discipline, developing a deep connection with riding on dirt and experimenting with the first technical modifications needed to adapt a dual-sport motorcycle to such a raw yet fascinating environment. Since then, this Dominator has become a personal symbol for Niko, so much so that he named it after his mother’s nickname: Rusinella.

Niko’s racing résumé speaks for itself: three titles in the French FFM Championship, a victory in the Krowdrace DMSB in Germany, and an Italian FMI Cup. What stands out even more, however, is the consistency of his performances and his ability to remain competitive on motorcycles with very different configurations — from traditional trackers to lighter, more refined specials.

Beyond his racing career, Sorbo is also distinguished by his commitment to spreading flat track culture in Italy. With the Dust & Fun project, a trophy designed to bring new riders closer to the discipline, he has played a decisive role in the creation of a true Italian flat track scene. The format, accessible yet technical, has taken root at the Tre Ponti Racing Motor Park in Ravenna, becoming a reference point for those who want to grow, compete, and have fun while respecting the true racing spirit.

Active on social and media platforms as well, Niko uses digital channels not to build an image, but to convey substance: preparation, passion, and a whole lot of dust. A professional who understands the value of behind-the-scenes work just as much as that of a bold outside overtake.

For me, Niko represents many things: a rider to admire on the track, a demanding client who always has something to ask for, but above all a true friend — one of those people you feel is part of your family, like a brother.

When we decided to put our hands on this bike — or rather, to recreate it from scratch — we both knew it wouldn’t be a simple restoration or a mere styling exercise. This project contains all of our passion: his for riding, mine for detail, functionality, and aesthetics. The bike had to perfectly meet his needs as a rider, with a chassis designed for dirt, speed, and the oval. But it also had to be beautiful to look at, because every welded curve, every drawn line, every chosen color tells something about me as well.

For this reason, the modifications were radical:

• Swingarm replaced with a longer, stiffer, and lighter unit derived from a CRF450
• Rear subframe made from aluminum tubing to lower the riding position
• Steering head angle set to 25°
• Fork with 41mm stanchions derived from a Honda CBR, with dedicated hydraulics developed by YSS
• Wheels supplied by Kineo, built to custom specifications to perfectly suit the project
• Fully hand-built aluminum fuel tank made from 1.5 mm sheet
• Redesigned triple clamps, CNC-machined from solid Ergal
• Custom-made stainless steel exhaust system, designed specifically for this bike
• Waterproof electrical system, with all electronics housed in an aluminum box integrated into the subframe, also contributing to structural rigidity
• Despite appearing to be a “simple” motorcycle, countless details were built from scratch using a lathe, CNC milling machine, and even 3D-printed components, demonstrating how carefully every single aspect of this project was developed.
• The engine also received significant attention, with targeted interventions to increase performance:
• Oversized high-compression piston
• Lightened crankshaft and flywheel
• Reprofiled camshaft
• Port matching
• Larger carburetor
• And many other technical refinements, all handled by master engine builder Claudio Lanconelli, the go-to engine specialist at Fuchs Workshop.

In this specific case, the graphics and paintwork were also done in-house, completing a project that is as racing-oriented as it is personal.

Special thanks to:

• SC Project, for supplying the materials used to build the exhaust system, including the beautiful silencer.
• YSS Racing Italy, for supplying and developing the entire suspension package

• Any idea of horsepower, weight, and/or performance numbers?

Roughly 60cv [59 hp], 109kg [225 lbs] without liquids.

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

It’s very powerful; the engine has undergone extensive tuning, helped also by the light weight. In fact, it was necessary to lower and lengthen the chassis to allow the rider to manage the bike effectively when entering and exiting corners.

• Anybody you’d like to thank?

My engine master Claudio Lanconelli, SC-Project for the material of exhaust system, YSS for the suspension. 

Follow the Builder

Instagram: @fuchs_workshop
Facebook: @fuchsworkshop
Outdoor Images: Christian Fussi (@chrifussi)
Indoor Images: Craig Stuart (@scrambler_ams)

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