Pocket Rocket: Sticking a Ducati 250 into a Moto3 chassis

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Most customs start out with a frame and motor from the same donor. But sometimes it’s a mix and match affair—and every once in a while, we see a truly exotic pairing.

This pint-sized racer from Analog Motorcycles is the most unique match-up to come our way: a 1968 Ducati 250 ‘narrow case’ motor mounted in a Moto3 prototype frame, and wrapped in a plethora of hand-made bits.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
The project kicked off about three-and-a-half years ago, when chassis specialists FrameCrafters reached out to Analog’s Tony Prust. They’d built a frame for an Analog project in the past—and were itching to work with the Chicago-based shop again.

Karsten of FrameCrafters made Tony an enticing offer: He had their first prototype Moto3 chassis sitting in the shop, and would Tony like to do a build with it?

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
“They would take care of fitting whatever engine I chose and get it to a rolling chassis, and we would take care of the rest. I said: ‘Of course!’”

The chassis was originally developed eight years ago, and has been used by a couple of pro AMA-level racers with the engine it was originally built for: a Yamaha YZ250. It’s a bi-metal design that combines chromoly tubing with billet aluminum junction points, and it’s a thing of beauty.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Joints are either bolted or bonded with space-grade epoxy. The idea, Tony tells us, is to make production easier, and to create the perfect amount of rigidity and flex where needed.

Around the time FrameCrafters pitched the idea, Tony came across three bikes’ worth of bits and pieces from vintage Ducati 250 singles. There was at least one complete engine in the pile, originally built for racing, so he sent that off to FrameCrafters to start mocking up the chassis.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
They stretched the Moto3 frame one and a half inches, not only to wedge the motor in, but also to make mundane maintenance tasks easier. “It could have probably fitted without lengthening,” explains Tony, “but then you would need to drop the engine to check or change a spark plug, and that was not going to work for us.”

FrameCrafters whipped up two front engine mounts, and a rear mount to attach the back of the engine to the frame and swing arm. Analog designed the subframe, which FrameCrafters then welded in to the Moto3 chassis.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Bill Bailey, machinist whiz and regular FrameCrafters collaborator, milled all the aluminum junctions by hand. When everything was buttoned up, Analog spent several hours giving the aluminum a brushed finished, then had it powder coated clear to preserve the hard work.

The Ducati rolls on rebuilt Showa suspension from an Aprilia RS125. A set of 17” Sun rims was laced up to a modded Honda CB550 front hub and a custom made Barnes quick-change rear hub.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Braking duties are handled by a full Beringer brake system, with HEL lines. Dunlop rain race tires round out the package: a KR189 up front, and a KR389 at the rear.

While FrameCrafters were fine-tuning the chassis, the leftovers from Tony’s pile of Ducati bits went to TJ at DemonTech. He put together another 250 engine, adding a 12V conversion and electronic ignition from Electrex along the way.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Other upgrades include a NOS Dell’Orto VHB27 carb, and a custom gearshift linkage to convert the bike to a left-side shifter. The kickstart lever had to be modified too, so that it would clear the rearsets and linkages.

As soon as Tony had the rolling chassis back in the shop, he started working on a wooden buck for the new tank and tail. “I had been wanting to make all the body work myself this time. I had a mentor by the name of Devlin Hunt coming in and helping me hone the metal shaping craft a bit more. I was already doing fenders, seat pans, number plates, etcetera—but not a tank yet.”

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
“I learned so much working with him, and he was an incredible mentor. He was a retired engineer and two-stroke guru, and was a self-taught metal shaper. He would not do any of the work; he showed me and then made me do it, which is exactly how I learn.”

“He unexpectedly passed away in February 2017, and that pulled all the wind out of my sails on the project.”

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Tony put the Ducati on the back burner and went back to customer projects for almost a year. “I worked on the metal shaping craft a little bit more in the meantime, building the KTM ‘ArchDuke,’” he says.

“So when I got to the Ducati fairing, I was a little more prepared. That was a big undertaking for me, and I am really pleased with how it came out.”

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
Giving the bodywork a racing theme to match the Moto3 frame was a no-brainer, but Tony also worked in a few nods to Ducati’s back catalog. The paint is a Pantah TL Europe-only color scheme, laid down by Artistimo Custom Design. The stacked headlights reference the 999, and the air vent bump on top of tank the 900SS.

Poking out under the tail is a stainless steel Cone Engineering ‘Big Mouth’ muffler, hooked up to a one-off stainless steel pie-cut header. The tail light—an Analog catalog part—is mounted under the subframe; “similar to that of a GP bike set up for rain,” says Tony.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
The smaller details almost outweigh the headline features on this firecracker. There’s a new wiring loom, built around a Motogadget m.unit blue Bluetooth-enabled controller. The speedo and bar-end turn signals are also Motogadget parts, the clip-ons are modified Vortex items, and the grips are from Cole Foster.

There’s a custom-mounted steering damper too, and Free Form Design machined up caliper mounts and rear set brackets. Capping it off is stellar upholstery from Dane Utech of Plz.B.Seated.

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis
“We wanted it to have all the race parts and trim, and look fast sitting still, but using a beautiful old Ducati single engine. Just to make people scratch their heads a little when they look at it—and think to themselves, ‘Why?’”

“To which we respond, unapologetically: Why not?”

Analog Motorcycles | Facebook | Instagram | Photos by Grant Schwingle

New from Analog Motorcycles: a Ducati 250 single engine in a Moto3 chassis

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