Ducati 900SS J63 by Revival Cycles

Austin's Revival Cycles continue to raise the bar with their impressive build portfolio, they custom build a Ducati 900SS, and now their J63 Cafe Racer is a nut and bolt reincarnation of Ducati's venerable Super Sport. Revival founders Alan Stulberg and Stefan Hertel pride themselves on building custom bikes that are “better than the original"

“The J63 started as a Ducati 900SS SP, a rare bike, but a dog had literally torn it to shreds. I bought it in Houston for $500,” Alan explains. “A client wanted a bike like our previous Ducati, the Pyro, only better.” It was time to build their first frame, and Stefan designed it in CAD, with a few limiting parameters: 18-inch wire wheels, twin shocks, all stainless everything, and no paint. Alan drew the frame on a napkin, which Stefan interpreted mechanically: “A scratch-built frame gave us complete control of the chassis geometry and suspension. The 18-inch wheels are an aesthetic choice but a compromise in performance; we used a 21-degree steering head angle for smaller trail and quicker steering, which also brings the gyroscopic precession axis closer to the rear contact patch.”

The steeper head angle increases fork flex from riding and braking loads, which Stefan helps cure by designing triple clamps without pinch bolts, which “create uneven clamping forces and reduce stiffness at the slot; we hold the fork tubes with a tapered collet, which applies consistent radial clamp force” for a stronger fork assembly. Designing the frame was “rather straightforward,” he says, “pulling elements from the 750 F1, round-case 750SS, and the 900SS in a new way that highlights the air-cooled engine and belt-driven cams, with geometry from a ’90s-era 250GP bike. Although selectively compliant frames are all the rage these days, this frame is deliberately stiff, as it’s not a full racebike. We used a semi-exotic stainless-steel tubing called Ferralium, which matches chrome-moly mechanically but has better corrosion resistance than 300-series stainless, so we can leave everything exposed; of course, with no paint to hide it, the craftsmanship has to be perfect.”

With a completely new-design frame, fork, and swingarm, the J63 is “very much an experiment” for Stefan. “Having changed nearly every variable, there was a lot of opportunity for mistakes,” Stefan says. “But with hard work we got it right the first try, and the way this bike rides is remarkable. The feel is intuitive and predictable—the chassis works with you.” Which is a good thing, as the J63 was finished at 8:30 on the morning Café Racer TV arrived to film Kevin Schwantz test the bike on Austin’s Circuit of The Americas. After several all-nighters, the Revival crew was bleary on the track, warning Schwantz to take it easy on the spanking-fresh machine. No dice: The former world champ did 10 full-throttle laps and loved it, giving highest praise to the handling and manageable power. “That was the ultimate test,” Stefan says. “It couldn’t have been any better.”

Source Cycle World