Apparently it was not a standard bike but one they built themselves. Pulled this off the Popular Mechanics website. Article was dated July 17, 2008. Erin Scottberg is the author.
"Dark Knight's Bat-Pod Took Up-Armored Road From Garage to Set
Re-inventing the motorcycle for the Caped Crusader took more than green screens and gadgets. Chris Nolan and Co. built a custom bike from plumbing parts and modded exhaust tubing, then loaded it with weapons and prayed the world's best stuntman on two wheels didn't fall off. The DIYers behind this summer's hottest film take PM for an exclusive look at the making of Batman's new ride.....
Enter the Bat-Pod, a motorcycle-ATV hybrid that lands eye-popping stunts sans CGI, a hand-built bike that fires grappling hooks—while shape-shifting.
After picking through junkyards, a local Home Depot and that surprisingly hands-on garage, Nolan and production designer Nathan Crowley took a month to assemble a foam-and-plastic model for Batman's new ride—enough like the Tumbler, but with a heavy-hauling look of its own. "But to actually have a look at what we were thinking, we went down to Warner [Brothers] and got the front wheels off the Batmobile," Crowley says.
When he first laid eyes on the Bat-Pod mockup, special effects supervisor Chris Corbould wasn't sure if his director actually knew anything about motorcycles. But that's what makes The Dark Knight at once a throwback superhero movie and a green-screen-light breakthrough in digital Hollywood: It turns fantasy into reality. And building a concept vehicle without a team of automotive engineers was one of its biggest challenges. "The gauntlet had been thrown down," Corbould says.
While the filmmakers and Warner Brothers have been tight-lipped about any vehicle specs in the movie, Corbould clearly had to reinvent how a motorcycle's systems make it run. Nolan and Crowley's original sketches had no tailpipe, but anything with a motor needs an outlet for exhaust. Weaving around the bike's carbon-fiber and Kevlar body and steel chassis, the design team built the exhaust system into the frame, ducting it through the hollow steel/aluminum/magnesium tubing. Two months later, the high-performance, water-cooled, single-cylinder engine—geared toward the lower end for faster acceleration—was ready to power the Pod."
