With a name like Rebels Alliance, it should come as no surprise that conventionality falls by the wayside at Sam Standfast’s workshop. The firm operates out of east London, with a small but highly dedicated team of like-minded artisans under Sam’s leadership. For them, Rebels Alliance is a lifestyle more than anything else, and that’s what really helps to glue their ideas together in a seamless manner.
The project we’re about to examine might just be the raddest one they ever came up with, appropriately nicknamed the Rough Diamond. Of course, the sobriquet was inspired by the motorcycle’s angular fuel tank, but that’s just one of many intriguing characteristics to be found throughout this build. Before we dive in for a closer look, let’s take a minute to talk about the donor bike chosen by Sam and his crew.
It came in the form of a Yamaha SR500 from the model-year 1979, which is perhaps one of the more conventional things about this project. The tried-and-true SR platform has proven its worth to the custom motorcycle community on countless occasions, thanks in no small part to its exceptional versatility. It also provides heaps of retro charm and all the reliability you’d expect from a Japanese thumper of its kind.
Given the model’s popularity among bike-modding artisans around the world, the guys at Rebels Alliance (or RA, for short) weren’t stepping on uncharted territory here. Their modifications are far from your typical SR one-off, though, making this bespoke flat tracker an incredible sight to behold. Upon arrival at the RA headquarters, the classic SR500 saw its bodywork, suspension, and brakes taken out of the equation.
Items like the subframe and exhaust followed suit, leaving Sam’s specialists with a blank canvas ready to be customized however they saw fit. The fabrication work started with the gas tank, which was meticulously shaped out of mild steel over a period of several weeks. Rebels Alliance built separate panels for each one of its facets, subsequently TIG-brazing them together into the final piece and polishing everything to a mirror finish.
Photo: Rebels Alliance
Behind the new fuel tank lies a handmade seat pan, supporting a very unusual saddle made up of seven individual parts. It certainly doesn’t look very comfortable, but the guys were happy to let practicality take a back seat on this particular occasion. The saddle is perched on a replacement subframe that’s been manufactured from scratch, and the tubing forms a skeletal tail unit of sorts, as well.
Up top, the structure is encased in a metal plate, while its flanks were left open to let the exhaust tips fill the space instead. We’ll get to the plumbing and other powertrain-related mods a bit later on, though, because there are many more structural changes to be admired on the Rough Diamond. At the front end, one may see a tracker-style number plate with integrated lighting.
It’s placed right in front of a Suzuki GSX-R750's upside-down forks, which were neatly connected to the SR500’s chassis via billet aluminum triple clamps. The same Gixxer also donated its twin brake discs and Tokico calipers to RA’s cause, and they’ve been linked to an aftermarket hoop of unknown origin. Things are equally intriguing at the back.
Photo: Rebels Alliance
A custom-made swingarm replaces the stock SR module, accompanied by a premium pair of adjustable shock absorbers from YSS. Furthermore, plentiful rear-end stopping power is the product of a higher-spec caliper and a modern aftermarket rotor. Completing the equipment in that area is a larger-than-stock wheel, wearing a Maxxis flat-track tire just like the front hoop. Now, let’s see what went on in the Rough Diamond’s cockpit.
You’ll notice a fresh handlebar perched on Apico risers, as well as a digital speedometer sourced from Motogadget’s catalog. Although there aren’t too many available details regarding the hardware located in the rider’s view, what we can say for sure is that the cockpit looks delightfully tidy. All the wiring was rerouted through the frame in order to clean things up even further.
Moving on to the engine upgrades, the most noticeable modification is the bespoke stainless-steel exhaust system. The plumbing took no less than two months to be fabricated in-house, and it runs a one-into-two layout with the header splitting right beneath the seat. Rebels Alliance performed some intricate mods inside the single-cylinder mill, too, first boring it out to 605cc and then installing a Carillo piston.
The latter boosts the engine’s compression ratio to 11.5:1, while a rebalanced crankshaft finishes off the new powertrain equipment. As you can tell, the Rough Diamond doesn’t have much in the way of paintwork, only featuring a stealthy coat of black on items such as the wheels, forks, and frame. Polished bare metal is the name of the game in most other areas, with the final touch being some motocross foot pegs perfectly suited to the flat tracker theme.
A bit of an artist himself, Silvian sees two- and four-wheeled machines as a form of art, especially restomods and custom rides. Oh, and if you come across a cafe racer article on our website, it’s most likely his doing. Full profile
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