Mule Motorcycle

By Mark Hoyer, editor of Cycle World. It’s awesome when a bike just comes together, when every part of your project seems like it was made to fall into place as if by some grand, cosmic plan. This is not one of those bikes.

No, “The Punisher” (named after the Marvel Comics anti-hero) earned its title by brutalizing the man who commissioned it, Bruce Baxter, and all those involved in the making of this big-block beast. Mule Motorcycles’ Richard Pollock—the builder who somehow brought together and massaged all the special parts into the stunning package you see here—wholeheartedly agrees that this XR1660 street-tracker lived up to its namesake.

“This bike stretched my imagination to the breaking point and beyond,” he says. “Every part, it seemed, was a design challenge all by itself. Many parts are the second or third version. It’s a prototype project that I thought would never end. There were times when I would get ‘fabricator’s block’ and my mind would go numb and blank for a month at a time. All brain space had been consumed. I didn’t even want to look at it!”

But, as you can see, all we want to do is look at it. And ride it, which is what Baxter does. In fact, in the tying together of all the vital components of this build, one key element was a 3.0-gallon fuel tank hand-built by Racetec, which gives Baxter enough range for the spirited rides he enjoys near his Northern California home.

Inspiration? “I grew up in the Bay Area, and in 1971, you could see flat-track racing just about any night of the week,” says Baxter. “I wanted to recreate the look of those bikes in a truly performance-built flat-tracker for the street.”

The project began nearly 10 years ago and has gone through many, many iterations. Perhaps the brutality of the build is reflected in the barely contained brutality of the riding experience. The Punisher rides like a barium beach ball with a thermonuclear-explosive means of propulsion. It doesn’t feel heavy, exactly, but it does feel incredibly dense. And, yes, explosive. Note the 100-cubic-inch, 130-horsepower/130-foot-pound Sportster-based heart, and also note the miles of aerospace-grade plumbing to help the engine’s internal breathing capacity and oil flow. It seethes when it breathes.

“I wanted a motor that was capable of 7500 rpm and a sustained 6800 rpm for street use,” says Baxter. “But getting an H-D-based V-Twin to oil correctly at these rpm was almost a year of development itself.”

Pollock’s take on the engine built by famed tuner Dan Baisley and further developed by Baxter and Dale Lineaweaver of Lineaweaver Racing? “I was sworn to secrecy concerning funds expended if his wife were to ever call.” Ha!

Foundation for the powerplant is a set of S&S cases, with Axtell cylinders and a pair of dual-carb Baisley heads fed by Bob Woods-modified Keihin carbs. “If you are going to build an XR-750 replica for the street, the engine has to have dual carburetors and true dual-carburetor heads,” says Baxter. “There is only one other set of dual-carb heads by Dan Baisley like these on earth.”

The development process saw the bike get completely stripped at least three times, including complete engine disassembly each time, with Baxter, vice president of operations for a communications startup, primarily doing the work.

Pollock was charged with getting the engine in the C&J frame, which had to be modified to accept this taller-than-XR-750 mill. “I called Dan because, assuming the 100-inch motor was a stroker, it was probably going to be taller,” says Pollock. “He took some measurements and it turned out to be 1¼ inch taller. Holy crap! That’s a lot. So with the intent of having the bike look, sit and work like a normal street-tracker, I kept the steering head in the normal position and then lifted the backbone at the rear to a more level attitude. This way, the bike wouldn’t get really tall and the motor wouldn’t get dropped down really low.”

The conventional fork is a 45mm Honda CBR900RR unit (chosen for its loose resemblance to dirt-track fave Ceriani) riding in A&A Racing triple-clamps, with a pair of Öhlins shocks on the beefed-up C&J swingarm. Brakes are Brembo titanium-pistoned Monoblocs. “When I ordered them in 2002, I said I wanted MotoGP-grade stuff,” relates Baxter. “Honestly, though, you don’t really need the brakes. When you roll off the throttle, the thing just stops!”

Sun rims carry—what else?—19-inch Goodyear dirt-track tires. The front hub is Yamaha XS650 and the rear is from A&A Racing, in XR-750 style.

As for the real story behind the naming of the bike, the kidding stops. “I lost my son in a car accident in 2005,” says Baxter. “Before that, all of us were having dinner with friends and the subject of tattoos came up. I started bragging that my kids didn’t have tattoos, didn’t have any earrings or other hardware. When I finished, my son, Adam, who was about 20 at the time, gently rolled up his right sleeve and here’s a tattoo of The Punisher. He was laughing his ass off. Adam loved motorcycles, he was a college wrestler and he really liked The Punisher. The ‘AMB’ under the logo on the tailsection are his initials.”

Seems to me that this is a motorcycle that shows just the kind of strength and dedication a Punisher fan would love.

Images by Andrew Wheeler of AutoMotoPhoto.

Thanks Kerry