Introduced in 1981, Kawasaki GPz1100 has been called the last king of the air-cooled superbikes, a fuel-injected 1089cc hot rod that ruled the street and strip until the rise of the liquid-cooled, aluminum-framed sportbikes. Said MCN in a recent retrospective of the machine:
“For a fairly brief, incandescent, riotous period in the early to mid-1980s, the ultimate incarnation of Kawa’s air-cooled fours became the GPzs.”
In 1983, the final incarnation of the GPz1100 appeared. Known as the ZX1100-A1, the bike boasted “Uni-trak” mono-shock rear suspension, anti-dive units on the forks, revised cams, a styling overhaul, and an improved power rating of 120 bhp — class-leading at the time. The whole GPz family was a dominant bunch, but as MCN declared, the 1100 was always “The Daddy” bike:
“The final GPz1100A was, and remains, some kind of ultimate. It was top dog at the end of the era of air-cooled superbikes.” —MCN
Enter our friend of Darren Begg of Canada’s dB Customs — a man who’s earned his reputation building some of the baddest, most well-executed superbikes on the planet, most of them air/oil-cooled monsters like the Honda CBX1000 restomod we recently featured. Suspension, brakes, wheels, and engines are all upgraded — while retaining the style of the original machine.
Now Darren’s back with the ’83 GPz1100 (ZX1100-A1) you see here, built for a customer in Texas. In true restomod fashion, this GPz has been brought into the modern age with Öhlins suspension, OZ Racing forged aluminum wheels, Brembo brakes, and a GSX-R600 swingarm conversion — one of the most challenging aspects of the build:
“Swingarm conversion was a bit of a challenge to determine the appropriate linkages to set the desired geometry and have sufficient clearances to achieve full range of suspension motion.” –Darren Begg
Then there’s the engine: 1170cc forged pistons, .410 lift cams, a welded crank, 35mm Keihin FCR carbs, and a 4-into-1 hand-bent titanium exhaust from Bito R&D. The engine has been Cerakoted and the paint sprayed by Sketchs Ink — no vinyl!
The Canadian roads have postponed testing, but we’ll be after Darren for riding impressions and a sound clip of this mean green godzilla come spring!
Kawasaki GPz1100 Restomod: Builder Interview
• What’s the make, model, and year of the bike?
1983 Kawasaki GPZ1100 (ZX1100-A1).
• Why was this bike built?
Customer commissioned build (customer from Texas).
• What was the design concept and what influenced the build?
Customer wanted a similar look to the GPZ’s built by AC Sanctuary in Japan, in green.
• What custom work was done to the bike?
1170cc Wiseco forged piston engine with 410” lift cams and welded crank. 35mm Keihin FCR carbs and 4-1 hand bent titanium exhaust from Bito R&D.
GSX-R600 swingarm conversion with Ohlins suspension and OZ Racing Gass forged aluminum wheels and Avon Spirit ST tires. All brakes by Brembo including RSC masters and levers with hydraulic clutch conversion.
Woodstock billet rearsets. Sculpture billet triple clamps. Koso GP gauge.
Paint and Cerakote engine coatings by Sketchs Ink (all paint no vinyl).
• Does the bike have a nickname?
• Can you tell us what it’s like to ride this bike?
Winter roads prohibit test riding until spring.
• Was there anything done during this build that you are particularly proud of?
Swingarm conversion was a bit of a challenge to determine the appropriate linkages to set the desired geometry and have sufficient clearances to achieve full range of suspension motion.