Mike Stewart and his ultra-rare Harris Magnum S…
Harris Performance is one of the most revered names in motorcycle racing, customization, and performance. Brothers Steven and Lester Harris, along with partner Stephen Bayford, founded Harris Performance Products in 1972, and it continues to be a family-run operation out of their workshops in Hereford, UK.
Harris made a name for themselves building chassis kits for Yamaha TZ and Kawasaki H2R racing engines. In the 1990s, they were one of only two private companies licensed to run factory Yamaha YZR500 engines in their own chassis for the 500cc Grand Prix World Championship class, and Suzuki later enlisted them to develop, test, and race the official Suzuki World Superbike GSX-R750 WT.
The company also developed a successful Moto2 chassis, was instrumental in the development of several of the new Royal Enfield models, and continues to be deeply involved in racing.
“The enthusiasm of the company for motorcycle sport is as strong now as it was in 1972, they are great supporters of the adage racing improves the breed.” –Harris Performance
Then there are the street bikes, most notably their one-off specials and legendary Magnum series of bespoke chassis kits, built for engines such as the KZ1000, GS1000, GSX1100, and even the Bandit 1200.
“The first bikes were just endurance racers on the road but then we made a proper road bike, the first Magnum, with a road fairing and fibreglass tank cover.” –Lester Harris, Classic Motorbikes
Among these was the very rare Magnum Model S — only ~20 built.
“The original was commissioned from Harris Performance by Alex Stuart, a yacht designer on the south coast who enjoyed fast touring and couldn’t get on with the Magnum 2 frame style, which splayed the rider’s legs apart due to the frame tubes going around the engine — hence the Harris solution, best described as a combination of a Magnum 2 and their F1 frame.” —MotorcykelGalleri.dk
Although the design retained the distinctive Magnum tubes going around the side of the engine, they ran more over the top, giving a narrower position for the rider’s legs. Stuart designed and manufactured his own bodywork for this bespoke “sports tourer” — a polarizing fairing design that many riders didn’t love, though owners are encouraged to hold onto the fairings if they still have them, as no molds exist to recreate them!
Recently, we came across this naked Magnum S from Mike Stewart of the UK, who’s been into motorcycles since he was a teenager in the late 70’s, riding and wrenching on a vast array of on-and off-road bikes.
“I started rebuilds in the mid-90s, although my first real challenge was a Yamagama which I started in 2014 — this was sold to fund the Harris which came into my garage in 2018.”
He works out of his home garage, which is well-kitted with a mini lathe, bike bench, air compressor, and more — plenty to rebuild a pair of two-stroke Yamaha DT’s, which get ridden most weeks. As for the Magnum, he’d been lusting after a Harris for nearly 30 years:
“My memories of these bikes were in the early 80’s — I had hankered for one since. Originally, I was going to restore it to what it should have looked like. However, the ‘S’ looked horrible with a big jelly mould fairing hiding the frame, so I decided to open it up so the engine, frame, and all could be seen.”
The engine is from a 1981 Suzuki GSX1100EX. Though it had only 15K on the clock, Mike completely tore down, vapor-blasted, and rebuilt with new bearings, seals, and the like.
The bike originally ran the standard GSX1100EX wheels, forks, brakes, and electrics, but Mike swapped these out for Ducati forks, R1 front wheel, Brembo brakes, GSX750R swingarm, and a Hayabusa rear wheel. The bike also received a complete motogadget rewire, including a Bluetooth wireless ignition and speedo. Next up is a set of smoothbore carbs, if he can find a set that don’t cost a king’s ransom.
“And it goes on, as they all do — it’s a hobby which keeps evolving. The bike gets used when I can — it’s not the most comfortable machine, but I can ride it for hours without too many aches or stresses.”
Below, Mike give us the full story on this bespoke sport touring monster!
Harris Magnum S: In the Owner’s Words
I’m 58 years old and been into motorcycles since the late 70’s. I started at the age of 16 on a Yamaha FS1E and progressed to a Yamaha DT175MX, been riding ever since on old and modern bikes. These include on and off road — DT, PE, WR, TL, Z1100, GPZ600, XJR1300, X7, Triumph, etc., etc. the list goes on and on.
I started rebuilds in the mid-90s, although my first real challenge was a Yamagama which I started in 2014 — this was sold to fund the Harris which came into my garage in 2018. I do as much work as I can to all my bikes, making brackets spacers and bespoke fittings. I recently made the alloy speedo housing for the Harris — just waiting on a clear lens. I have a reasonably kitted out garage with limited space, but it does the job. Mini lathe, bike bench, compressor, and the Dremel, a must for any enthusiast.
I have also rebuilt a 1975 DT250 and a 1981 DT175MX — all my bikes are roadworthy and get ridden most weeks. I am not what you would call a purist, but then the Harris products were never for the production standard types. It’s a bit of a kit bike, I suppose, mixing old and new for a bit of fun.
This year’s been a bit of a wash out in the UK, rain and covid, many events cancelled. Luckily, we have some local meeting places around Oxford so we can get out as much as possible.
The frame is a 1980s Harris Magnum S model, designed as a full fairing bike for streamline cruising. The S model is quite extraordinary. Built using a 1981 Suzuki GSX1100EX, with originally standard wheels, forks, brakes, and electrics.
I purchased it from Northern Ireland in June 2018. The guy I bought it from was the second owner and he cafe racer’ed it. He did keep all the original fairings, etc., which I have stored, so if required it can be rebuilt as the standard (non-standard) bike it would have been in the day.
Harris only made a handful of “S” models, approximately 20! My memories of these bikes were in the early 80’s. I had hankered for one since, originally, I was going to restore it to what it should have looked like. However, the “S” looked horrible with a big jelly mould fairing hiding the frame, so I decided to open it up so the engine, frame, and all could be seen.
The engine had done only 15k miles. I dismantled it and vapour-blasted the crank case and cylinders to base alloy — it has been left with this finish. New bearings, seals, etc., and a complete rebuild including carbs…several times to get it running well.
The second rebuild was suspension and the third rebuild was wheels — Ducati forks and brakes.
A complete motogadget rewire with Bluetooth wireless ignition and speedo.
And it goes on, as they all do — it’s a hobby which keeps evolving. The bike gets used when I can — it’s not the most comfortable machine, but I can ride it for hours without too many aches or stresses.
Next steps are smoothbore carbs, but they are so expensive in the UK, so on the lookout for a race set which can be adapted — oh and might have the wheels polished.