It’s always been the little bike that could, the Yamaha SR400/500, a motorcycle that can be just about anything you want it to be. The vast bulk of them constructed since 1978 have served as admirable commuters, some get a small serving of modifications to make their owners smile, and then there are those who turn the simple machine into a single sensation. Enter Sydney’s Giovanni of GM Motorcycles, who was on a tight schedule to turn the sweet SR into an absolute showstopper in just six months. But his 1988 Yamaha SR400 wasn’t just created to wow the judges at the 2024 Machine Show; it was to follow up with a one-two punch, and the newly crowned trophy winner dubbed ‘SR540MX’ is now set to hit the dirt track with a boom.
Giovanni is a super-talented young builder and fabricator, and that was absolutely confirmed when over the weekend he took out the People’s Choice Award at the 2024 Machine Show and backed it up by standing on the podium in the Builder’s Choice Award category too. Normally, such achievements are years in the making, but this young gun was on a mission. “The bike was built between October 2023 and April 2024. So it was six months of pushing myself to get everything from my mind to the bike without compromising or leaving any details behind. I clocked about 400 hours in total; 300 hours just for metal shaping, frame mods, and exhaust pipe,” he tells us.
And with the bike having a dual purpose of requiring show-stopping looks and race-winning pedigree, it might seem to some that Giovanni had set himself an impossible task. But watching the build unfold on social media, it’s clear this is a guy who knows how to get it done. Setting to work on the ’88 frame, this was not a case of simply welding on a hooped tail. Instead, careful time was taken to ensure the chassis was in first-class condition and then get the geometry right to spin and win on the dirt track at places like Nepean Raceway. And Gio’s decision to convert the bike to single shock also meant some extra careful fabrication work was required too.
Having welded in the new upper mount and set the chassis up for more modifications to come, he took to the steel with a die grinder to get every corner and crevice painstakingly smooth. Then it was time to dive into the Prismatic Powders catalogue to select a very special colour to be laid down, with the glorious Illusion Purple a four-layer job. Now the process could begin in turning the sweet little SR into an angry track monster, and it all starts with a new swingarm taken from a ’02 YZ250, which has been prepared to perfection. This allows for the fully adjustable Ohlins shock from a Ducati Supersport 939S to be fitted, letting Gio carefully dial in his ride.
At the front end, the same Yamaha Motocross dirt bike, the YZ250, donates its inverted forks, which have been customised and lowered internally by 100mm. The YZ hubs are retained too, powder-coated, before being laced up with stainless spokes to beautiful Excel rims in gold, all wrapped up in battle-ready Michelin Starcross 6 rubber in a medium-soft compound. Steering duties fall to a nice set of black bars that have been kept strictly business. While the braking system is all YZ stuff, a wise decision given the quality of the equipment, from the hydraulic brakes to the foot controls, it’s all been very neatly grafted onto the SR.
And that fabrication work only gets better with the mind-blowing body: “The metal work was done at MotoRRetro; I couldn’t make this project a reality without their knowledge and equipment.” But it’s Gio’s talent that really shines through. The stock tank might remain in place, but it’s now one very special piece. The knee dents are beautifully sculpted into the factory steel, and the same can be said for the flawless indents created for the new forks to clear. Front on, it’s all business, a number board letting the timekeeper know it’s number 15 crossing the line for victory, and that hand-formed front fender just might be the best MX-styled piece we’ve ever seen.
Being a flat track monster, the tailpiece is all-important, and the single-piece unit, which includes the sideboards, is yet another stunning example of what Gio can achieve with a piece of metal and a few machines. And while he was at it, he also hand-formed the fork covers, splash guard, bash plate, and chain guard, each as brilliant as the next. Bad Arse Trim Co. did a brilliant job shaping up a gripper seat with a show level of fit and finish, and then it was time for colour, but the usual Yammie looks just weren’t Gio’s thing. “Then one day I went to pick up some parts at a local Yamaha dealer, and I saw a brand new YZ250 50th anniversary in purple and white… I fell in love with those colours straight away.”
But keeping the show and go an equal match meant making one monster motor, and this mighty single doesn’t miss. The crank is from an SR500 and has been topped with a +3mm high comp piston, while the head has been ported, flowed, and stuffed full of oversized valves. To feed the fire, Gio has tuned up a big pumper carb from a 2010 YZ250 and then, once again, shown off his incredible fabrication skills with a smooth-as-silk stainless exhaust that exits under the seat from a Leo Vince muffler. The bike was kept meticulous for the show, but “From the little celebratory ride I had, I could tell it’s crazy quick compared to the stock engine.” And now, show trophies under his arm, Giovanni will hit the track, ready to prove that ‘SR540MX’ by GM Motorcycles is the ultimate all-rounder.
[ GM Motorcycles | Photography by Cam Rogers ]