This Custom Yamaha XT500 Is a Succulent Tribute to Vintage Motocross Bikes

We’re always delighted to talk about their incredible machines, be they scrambled, caffeinated, bobbed, or chopped. These Aussies can knock the ball out of the park regardless of what genre they choose to go for, and that’s a huge part of the reason why they’re so successful. Scramblers seem to be the most common specimens in PBM’s build archive, with the one pictured above being among their latest creations.

It started out as a beat-up Yamaha XT500 from the model-year 1976, which had been partially modified prior to crossing Tom Gilroy’s doorstep. The project had a bit of a rough start, as the bike was initially taken to a different shop by its owner, Clint. He soon found out that said garage didn’t have the necessary know-how to make his vision come true, so the old XT was handed back to him in an unfinished state.

Then, Clint got in touch with Purpose Built Moto of Gold Coast, Australia, confident that Tom’s specialists would be able to take it across the finish line. Of course, the guys were more than happy to embrace this challenge, and the fruit of their labor is absolutely delicious in so many ways! With the classic Yamaha on their workbench, they took it apart and dug straight in.

As their first port of call, PBM tackled the motorcycle’s suspension. The OEM paraphernalia got ditched altogether, and the inverted forks of a Kawasaki KX450F can now be spotted at the front. They’ve been revamped and shortened by Costanzo Racing Tuned prior to installation, while the XT’s rear end gained a pair of adjustable shock absorbers from YSS.

Down in the unsprung sector, we find new Excel wheels measuring 21 inches at the front and 18 inches at the back. The rims are enveloped in chunky dual-purpose knobbies, and the aforementioned Kawi also donated its front brake along with the suspension goodies. Bespoke aluminum guards keep the fork lowers out of harm’s way, but our protagonists came up with a custom skid plate, as well.

On the main bodywork front, you will still see the factory XT500 fuel tank taking pride of place center-stage. All the other garments have been fabricated from scratch, though, with the raddest bits and pieces being located at the front end. A sizeable, high-mounted fender is placed right below the bottom triple clamp, but we’re even more intrigued by the handmade headlight shroud found up top.

It surrounds Purpose Built Moto’s proprietary 4.5-inch Flashpoint headlamp and is flanked by small LED turn signals. Further back in the cockpit area, you’ll be greeted by Daytona instrumentation and a fresh, motocross-style handlebar from ProTaper. The latter is equipped with plain PBM switchgear, high-grade control levers, and underslung bar-end mirrors, as well as a pair of aftermarket grips to bring the package full circle.

Turning our attention to the rear end, we come across a modified subframe topped with a tailor-made saddle. Behind the new seat lies a custom-made rear fender, whose southernmost tip holds the license plate bracket and an integrated LED taillight. One-off side covers are located on the flanks, neatly concealing a modern battery and the bike’s upgraded electronics. Speaking of the electrical hardware, it now includes a Black Box controller from PBM’s catalog.

Nuts and Bolts Development supplied an electric starter module to make Clint’s life a bit easier, but the original kick start was left in play to act as a back-up. Purpose Built Moto really went to town with the performance upgrades, treating the XT500’s engine to a complete overhaul inside out. During the rebuilt, they fitted items such as a high-compression piston, larger valves, and a brand-new camshaft.

There is also a replacement clutch mechanism, and all the standard breathing equipment got ditched to make way for higher-spec alternatives. Air flows in through a Mikuni carburetor, while the exhaust fumes are routed via bespoke high-mounted pipework that ends in a Staintune muffler. An FMF PowerBomb unit is part of the exhaust system, as well.

Finally, the last piece of the puzzle was the motorcycle’s color scheme, and this job was outsourced to Justin Holmes over at PopBang Classics. A tasty shade of yellow was chosen as the base hue for the bodywork, with black and white highlights accompanying it all throughout. The fuel tank is adorned with a snazzy reinterpretation of Yamaha's speed block design, while the side covers bear the number 76 over a black background.