Inheriting a project bike from another workshop is a huge gamble. There could be parts missing, the engine could be shot, or the title might not be kosher. Yet, bargains can be had if you know what you’re looking at—and if you have the skills, equipment, and time.
That’s how Purpose Built Moto in Gold Coast, Australia inherited this 1976 Yamaha XT500. An existing customer and friend of the shop, Clint, brought the thumper to them because of the extensive custom work required to resurrect it. The previous shop had bitten off more than they could chew—but this wasn’t an issue for Tom Gilroy and the PBM team.
“Clint knew about the standard of our work, due to his Purpose Built Moto Yamaha DT400,” explains Tom. “Clint’s DT400 was the build that started us down the road of developing our own vintage motocross-inspired scrambler style and applying it to a number of custom bikes.”
With the client on board and the vision set, the crew tore into the bike like a drop bear on a tourist. The first challenge was to modernize the suspension and improve the stance.
The front end from a Kawasaki KX450F was grafted onto the Yammie frame. The forks were re-valved and lowered by Costanzo Racing Tuned, while a pair of lengthened YSS shocks were bolted onto the back end. The dirt-friendly 21F/18R Excel wheelset is new, as are the handmade alloy lower fork shrouds and engine bash plate.
The bodywork is a collection of handmade and new parts. The headlight shroud and front fender were made from scratch, with the fender featuring a beaded edge in the style of the original. The 4.5-inch Flashpoint headlight, Hollow Tip indicators, and tiny daytime running lights are all from the PBM catalog.
Behind the shroud sits a Daytona DEVA digital dashboard, controlled via PBM switches that are wired in using the shop’s signature ‘Black Box’ control module. Custom bar-end mirrors are slung low on new ProTaper handlebars.
The Yamaha XT500’s fuel tank is original, but the mounts are modified and indents have been added to accommodate the chunkier forks at full steering lock. New side covers adorn the bike too, with the electrics and battery box organized inside.
PBM had to install a bigger battery, to power a nifty electric start kit from Nuts and Bolts Development in France. Kicking over an air-cooled 500 is trying at the best of times, so the electric start kit makes it a helluva lot easier to live with. The kickstart is still fitted though, so if Clint is feeling brave he can roll the dice on a Friday night in front of the pub—and he has a backup if the battery dies in the bush.
Purpose Built Performance is PBM’s relatively new in-house engine-building division, so the electric start wasn’t the only upgrade. A high-compression big bore kit was fitted, along with a polished head and oversized valves. The XT500 mill is also running a hot cam, a performance clutch kit, and an upgraded charging system.
A stonking Mikuni pumper carb throws fuel down the thumper’s throat, with hot air exiting through a custom header with an FMF Powerbomb and a Staintune end can. The classic muffler sits high, bolted to the trimmed and looped subframe and flanking the custom rear fender. Made in the same style as the front fender, it has a tiny LED taillight integrated into the back of it.
The Yamaha XT500’s bread loaf-style seat is gone—replaced by a custom unit that tips its hat to the original shape, but with a slimmer profile. It’s been wrapped in a gripper fabric by Timeless Auto Trim. PBM LED turn signals and a neat license plate mount finish off the tail.
With the body and engine work complete, attention turned to the paint and graphics. Given that this XT is a little more aggressive than the last one that PBM built, Tom went through the 1970s Yamaha motocross catalog. Taking inspiration from the YZ400 motocrosser, Tom settled on a classic yellow speed block design, which was expertly laid down by Justin at Popbang Classics.
“The last Yamaha XT500 scrambler we released lit a fire in the hearts of many riders,” says Tom. “We’ve had countless stories of adventures and mishaps on these prolific old bikes—as we put the finishing touches on this build it was no different. With a heavy dose of nostalgia and an equal measure of modern upgrades, this XT500 has got to be my favorite one yet.”
From arriving at their workshop in boxes to leaving like this, this vintage scrambler is another winner from Purpose Built Moto. The entire design is not only classic, but it’s also cohesive, subtle, and stunning. Any motorcyclist with breath in their lungs would love to have it in their garage… or living room.
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