Almost immediately upon its release the Honda CX500 was derided and ridiculed, the nicknames were rarely kind and with prices reduced they became the go-to motorcycle for two-wheeled couriers. But with an engine designed by legend of motorsport Shoichiro Irimajiri, it’s clear that a new generation of custom builders have seen the Honda in an all-new light. What isn’t known to many is that in some markets Honda released a sport version of the bike, vastly improved, but it was too little too late. Now 40 years on, utilising their motorsport experience, Bulgarian builders Tossa R have released their own take on the CX500, giving it the full sportsbike treatment.

While anyone can throw a set of modern forks on an old motorcycle and call it improved, the reality is much more complex when it comes to giving the rider of commuter bikes a true sportsbike experience. It is, however, not impossible with club racing around the world seeing a host of unlikely machines turning in fast times on the track. So utilising their own racing experience and years of bespoke craftsmanship, the Sofia based outfit led by Asen Zahariev decided that having given the treatment to many other machines, it was time to try their hand at a CX500.

Starting with a first registered in 1986 model, the bike was pulled down to a bare frame in the Bulgarian workshop. Knowing what they had planned the chassis came in for a serious makeover, not only for visual changes but to provide a more rigid foundation. At the rear the subframe was cut off and the section above the centre post removed. Then over the top, a new steel plate subframe is welded along the backbone and extends back to provide the seat support. Finally, it was coated in gloss black and put back together with all new stainless bolts.

To turn it into a roller a quality suspension package had to be pieced together and the team didn’t hold back. At the front new bearings and a steering stem change allow the full USD fork setup from a 2006 Yamaha R1 to be slotted in. The decision was also made to utilise the R1’s big brake package that combines four-piston calipers with dinner plate-sized 320mm rotors. But interestingly enough, rather than use the Yamaha wheel that came with the setup, Tossa R chose to retain the stock CX unit. Not only does this keep the distinctive ’80s look, but the Comstar “Boomerang” are a true multi-piece full aluminium wheel, they’re light.

Shifting their attention to the rear and the decision to use a later model donor bike pays off. Rather than dealing with a twin shock setup the Pro-link is a dramatic improvement. But the crappy factory shock was never up to the task of controlling the weight of a shaft-driven bike. So diving into the Honda section of the Ohlins catalogue they came away with one hell of a replacement. Originally designed for a CBR1000RR, they ticked all the options boxes that even gives the fully adjustable unit a gold collar to hold the remote adjuster. With a disc brake rear and two-pot caliper, they now had a bike that turned and stopped with serious ability.

The visual overhaul also starts at the rear end, while both rims are painted black, the back end gets a full moon disc cover. Before the front is wrapped up in a Heidenau tyre and the rear a grippy Continental Attack. Hovering above the rubber is the new seat unit, a single saddle that has been stitched together in the bikes colour scheme. Then a removable rear cowl was added, allowing a change in looks with just two screws, but when attached has the minimalist modern sportsbike aesthetic down pat. The big tank of the later CX’s is as distinctive as can be, modified to suit the new subframe it is then painted in a stunning Honda red and white colour scheme.

Of course, any sportsbike needs an engine to match, and while you can never make the 500cc V-Twin a monster, there is plenty of room for improvement. Stripped down and overhauled it now looks its Moto Guzzi best with a full blackout job and polished details. The same treatment extends to the rebuilt carbs, wearing pod filters, they’re polished to perfection and the fuel bowls are given a coat of black. The exhaust, however, is where things really shine, the stainless system first giving the hot gases a nice straight path to travel before winding their way tight to the underside of the bike and spitting flames out of twin custom cans.

The accessories don’t play around either, if it can be made more sporty it has been. With a pair of custom adjustable rearsets for the feet and clip-ons for the hands. Machined adjustable levers let every last detail be fine tuned for the rider, who gets better feel at the bar thanks to a radial master cylinder. A single Daytona instrument feeds back all the vital signs and lighting the way is a very clever selection, a neat headlight from a Brixton 500 provides old school looks with modern power and custom ears allow it to be mounted up. It may have been a common commuter in its day, but summoning the spirit of Shoichiro-San, Tossa R have given the stale CX500 a genuine Samurai like sportsbike transformation.

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