Slovakian Supermono: Jawa “JSA 650RR”

Jawa / Suzuki / Aprilia = JSA 650RR…

It’s easy to take for granted the opportunities many of us have to own and work on our own motorcycles. Recently we heard from Roman Juriš of Slovakia, who grew up in communist Czechoslovakia, where outdated Jawa machines were just about the only motorcycles available, and opportunities for customization were “almost zero.”

He worked for a year in motorcycle development at a moped factory before his mandatory military conscription, and didn’t ride again for 20 years — not until the fall of the Iron Curtain:

“I simply didn’t have the money for a motorcycle. It was only after the fall of communism that normal life began in our country and I was able to buy the first motorcycle wreck from which the JSA 650RR was created.”

Starting with a 1985 Jawa 350 type 634, Roman set out to create a machine with “knee down to asphalt” riding characteristics — quite the challenge for such an outmoded machine, especially a wrecked one.

With limited budget and parts availability, Roman had to use what was at hand, working in his 4×4-meter basement. He swapped in the 650cc Rotax single from an Aprilia Pegaso — more than doubling the horsepower — and built the rest of the frame to hold it. The suspension and wheels come from a Suzuki donor, and the tank and tail are GS500 units.

Nicknamed the JSA (Jawa / Suzuki / Aprilia) 650RR, the completed supermono was decked out in Yamaha-inspired “combat colors” and ridden to the limit:

“It was a different world compared to the original Jawa. At the age of 46, I put my knee down on the asphalt for the first time on this bike.”

This was Roman’s first build, and as Slovakia’s motor vehicle regulations tightened, the JSA was no longer street legal, so it’s now in a small private museum in the Czech Republic.

Below, we talk to Roman about his history and the build. Stay tuned for more creations forthcoming from the Slovakian builder!

Jawa 650RR: Builder Interview

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

I am 58 years old (young) and I rebuilt my first motorcycle when I was 16 years old. I installed two exhausts pipes on a two-stroke Jawa 50cc. I messed up the performance, but I was just a local dude. I grew up in socialism and the possibilities for customizing were almost zero. The only motorcycle available was an outdated Jawa 350. I had a front disc brake and fairing on it rather than factory.

As an 18-year-old, I worked for one year on motorcycle development in a moped factory. Before I learned anything, I was recruited as a soldier. After my mandatory military service, I stopped riding motorcycles for 20 years. I simply didn’t have the money for a motorcycle. It was only after the fall of communism that normal life began in our country and I was able to buy the first motorcycle wreck from which the JSA 650RR was created. I have always modified motorcycles as a hobby, never professionally.

• What’s the make, model, and year of the donor bike?

The documents were issued on Jawa 350, type 634, year ~1985.

• Why was this bike built?

I wanted to see if I could build a simple motorcycle like the Jawa factory was supposed to build. The main condition was “knee down to asphalt” riding characteristics.

• What was the design concept and what influenced the build?

I was a big fan of Yamaha racing bikes from the 70s, so I chose such “combat” colors.

• What custom work was done to the bike?

Jawa / Suzuki / Aprilia = JSA. Only the two bottom tubes remain from the original Jawa cradle frame; I made the rest of the new frame. I installed an Aprilia Pegaso 650 engine in the frame. The wheels and suspension come from an unknown Suzuki. The tank and rear fairing are from a Suzuki GS500.

• Does the bike have a nickname?

I think JSA is a sufficient nickname. While sorting through the photos, I found the “Reuma Racer” label. It was more of a joke than a nickname.

• Any idea of horsepower, weight, and/or performance numbers?

The Aprilia engine was purely stock, so it had about 48 hp. Compared to the original 23-hp Jawa, it was a super performance incrase. The weight was also comparable to the original Pegaso. The Jawa weighed around 150 kg.

• Can you tell us what it’s like to ride this bike?

It was a different world compared to the original Jawa. At the age of 46, I put my knee down on the asphalt for the first time on this bike.

• Was there anything done during this build that you are particularly proud of?

Everything I did on this custom was quite new to me. I was proud of myself for even putting it together and riding it. After some time, the rules for technical inspection got stricter and the motorcycle could not be used legally, so it ended up in a small private museum in the Czech Republic.

• Is there anyone you’d like to thank?

To my wife for allowing me to devote myself to motorcycles again after so many years. She may have regretted it many times since then, because I fell irrevocably into this passion.

Follow the Builder

I am an occasional correspondent for the Slovak website motoride.sk under the name “Romoto“. Here you will find my articles about motorcycles, written with love and passion for construction and customising.