ProtoWorks Manufacturing builds an air-cooled, 160-hp superbike…
Introduced in 1980, the Suzuki GS1100E quickly became the undisputed King of the Superbikes, rocketing through the quarter mile in 10.99 seconds at 120.8 mph — the world’s first ten-second production street bike. Cycle World named it Superbike of the Year for three consecutive years, and sixteen-valve engine, boasting “Twin Swirl Combustion Chambers” (TSCC), received nearly universal praise. Said Cycle in 1982:
“As things stand now, three out of three of the quickest and fastest motorcycles Cycle has ever tested have had the big-inch 16-valve Suzuki engine (’81 GS1100, ’82 Katana, ’82 GS1100).”
Enter Bill and Evan Gregory, the father/son team behind Ontario’s ProtoWorks Manufacturing, which specializes in restomod superbikes, prototyping, and small-batch machining. Last week, we featured their stunning 1990 Honda CB-1 restomod, which took home a top 10 finish in the builders’ competition at the 2020 Motorcycle Supershow in Toronto. Now they’re back with this ’83 GS1100E, which was actually their first build together and also took earned a top 10 finish!
Working out of their basement machine shop, the duo spent over 2.5 years on the project — and it shows. Only the engine, frame, and bodywork remain from the original machine.
“Other than the updated forks, brakes, wheels and instruments, everything else was designed, machined, fabricated or 3D printed by us.”
One of the most impressive components is the three-piece swingarm they designed and machined from solid aluminum — a stunning piece of work. The electronics are now housed in an aluminum skin stitched into the frame, replacing the rear fender, and the paintwork is inspired by Suzuki’s 2020 GSX1100. Then there’s the engine, which has been punched to 1260cc with JE Pistons, Web Camshafts, a Barnett clutch, and an in-house port and polish job. Says Bill:
“With the motor cranking out about 160HP, this bike is as fun to ride as it looks.”
Below, we get the full story on this restomod superbike!
Suzuki GS1100E Restomod: In the Builder’s Words
This bike represents a 2.5 year project undertaken by me and my son. We entered it in the builders competition at the 2020 Motorcycle Supershow in Toronto, where it earned a top 10 finish in the cafe racer category. It would have been nice if they had a Resto-mod, classic superbike, or a similar category for us to compete in, because this bike is definitely not a cafe racer.
All work was performed by me and my son. We are both machinists/fabricators/tuners. We have a complete machine shop in our basement consisting of several conventional & CNC metal working machines. Our garage serves as our tear down, fabrication, paint, final assembly and engine tuning area.
The only original parts that remain are the motor, frame & bodywork. Other than the updated forks, brakes, wheels and instruments, everything else was designed, machined, fabricated or 3D printed by us. For our next build (currently in process), we are machining triple clamps, brake calipers and several other bits of our own design.
The front end is from a 2001 Yamaha R1. The swing arm was machined from solid aluminum and assembled in 3 pieces.
With each build we continue to refine the design and manufacturing process of our swing arms in an effort to reduce the weight while maintaining maximum strength and reliability. The net weight is slightly heavier than a fabricated version, but the end result is a stunning work of art.
The paint scheme was inspired by the 2020 GSX1000 model. The seat was shaved down to render a sleek line.
To further clean up the lines we replaced the rear fender with an aluminum skin stitched into the frame and integrated it with the enclosure for all the electronics. We replaced the entire electrical circuit with an M-Unit, anti gravity battery and Dynatek ignition system. The only items remaining from the original circuit is the voltage regulator and starter solenoid.
Engine work consists of the following: displacement increased to 1260cc (JE Pistons), mild cams installed (Webcams), head ported & polished (performed by us), heavy duty clutch plates & springs (Barnett), 36mm Mikuni RS series carburetors. With the motor cranking out about 160HP, this bike is as fun to ride as it looks.
It was a pleasure working on this project and equally pleasing to see the final product.