In the early ’80s the big bad Suzuki Katana shook up the motorcycle world with its aggressive German design and dynamite Japanese performance. While many of those GSX1100 models live on today in everything from original trim to full racer in the hands of Team Classic Suzuki, only a few remember its siblings. One of the babies of the bunch was the GSX400 and when young Dutchman Willem Heeringa realised he had a rare locally delivered four cylinder model, rather than the plain little twin, he knew he had an excellent donor on his hands. The mechanical engineer decided it was his chance to learn about two-wheels and set about building the 1983 Suzuki GSX400F into a classy cafe racer that’s the perfect mix of old and new.

Living in a small town near Sneek, in the Netherlands, Willem is in the process of completing his Masters in Mechanical Engineering at Delft University of Technology, where he also completed his undergraduate work. There he was part of the student team who built an electric race bike, young Willem designing the trellis frame. With a neighbour obsessed with bikes it all started to pile up to the point that he knew he had to build his own. Finding the Suzuki GSX400F sealed the deal and it was time to make the little Katana into a classic cafe bike.

That was until he found a set of USD forks and a spoked rim that would fit and rather than a simple resto-mod, he decided to push his chips to the centre of the table and go all in! Starting with the frame it’s clear to see Willem took his schooling seriously and he’s reworked it back into picture perfect condition. Then it was time to ditch the rear subframe with the grinder in hand and chop all of the twin shock mounting hardware off. “A friend of mine is a really good fabricator and made me a custom subframe and braced the swingarm in preparation for the monoshock.”

Based on his own trellis-style design the swingarm is light years ahead of the factory item with plenty of strength and rigidity built in. With a new mount added to the frame the right shock was selected to carry the load and while in the full swing of fabricating a custom rear hugger was also welded into place. Above the new subframe is a brilliant piece of work, ultra-clean in its lines, the upswept rear hoop design shows off the mono-shock conversion while providing the foundation for the cafe racer bodywork to come.

Having gotten the rear end on track the front was in for a full makeover and thankfully the tiny factory forks were discarded. In went a modern set of USD units that required a custom designed and CNC’d top yoke and change of steering stem to fit. The hub that made the conversion to spoked rims possible comes from a GS550, with custom adapters and bushings next on the list to allow the modern twin brake disc setup to work. Clamped by twin pot calipers the little GSX finally has some serious stopping power with custom lines to supply the fluid.

The rear hub was taken from a CB550 and with both ends laced up and the rims wrapped in Bridgestone Battlax rubber, Willem was ready to roll. Turning his attention to the looks, the tight lines of the Katana series were not to his liking. “I did not like the length of the tank, so I shortened the original one.” But it still wasn’t right, so when you can’t find what you like you just have to build it and the new tank and tail cowl completely transform the look of the bike. The combination of exaggerated knee dents, glossy two-tone paint and classic leather for the seat leave the Suzuki dripping in its own unique style.

But good looks aren’t great if you can’t go anywhere, “The engine had 80k kilometres on it and I wanted to learn about motorcycle engines so I took it apart.” From new gaskets and seals, a decked head and replaced piston rings, Willem ensured no stone was left unturned in giving the shortblock a new lease on life. The factory carbs were overhauled and given new filters before it was discovered the factory headers were hitting the new tyre. Not one to stress, our young Dutch friend simply used it as an excuse to build a full stainless steel exhaust system.

The little touches are just as clever as the big, a full re-wire ensures that the GSX is as neat as can be. While a custom designed and fabricated rear number plate holder serves its job brilliantly. Up on the clip-ons the bars were decked out with all new grips and high-end push button switchgear. With a single headlight unit, ultra neat front fender install and custom mounted rearsets ensuring all the practical aspects of the build are finished out flawlessly. What was meant to be a simple resto of the baby Katana has turned into a showcase of everything Willem has learnt so far and the young mechanical engineer need only add his cafe racer to his resume to ensure his future success is a certainty!

[ Photography by Floris Velthuis ]