Honda CB450 K0 ‘Runcible Racer’

Honda CB450
The Honda CB450 K0 has a very secure place in motorcycling history books. Nicknamed the ‘Black Bomber’ on account of the Ford Model T-style paint choice, it was the first volume-produced motorcycle powered by a DOHC engine. And it still looks good today.

Australian Cliff Overton fell under the spell of the CB450 a couple of years ago. Out of the blue, he got the chance to own one—and jumped at it. “I wasn’t looking for a project, but this bike found me,” he says. “A guy at a swap meet said he’d found an old bike lying in a field in Colorado, USA. He was over there hunting for old pick up trucks to bring back to Australia.”

Honda CB450
Fast-forward six months, and the CB450 K0 arrived at Cliff’s house after a long sea journey with said pick up trucks. And Cliff realized he had a big job on his hands. “I’ve played with bikes before, but only as far as a few bits around the edges,” he admits. “Never got inside an engine before—so this was a bit daunting!”

Bravely, Cliff got stuck in and pulled the engine apart. He got the head and cases bead-blasted and vibra-polished back to as-new condition, and decided that this was going to be what he calls a ‘resto-rod’ project. “I liked the look of the Black Bomber and wanted to make a bike that Honda could have made in the late 60s if they wanted to market a café racer special.”

Honda CB450
The tank is from a later K1 (“I like this tank better than the K0 tank”) and the seat is from Roc-City Cafe Racers, trimmed to fit. The rearsets are from Dime City Cycles, and the sporty little exhausts are actually late 60s aftermarket new-old-stock for the CB450—a real eBay find.

“The hardest part to get was the original headlamp and gauge set,” Cliff recalls. “I wanted one from the start, because it’s one of the ‘hero’ parts that tells folks that this is a Black Bomber.”

Honda CB450
Performance mods? None so far. “The engine runs stock ‘second oversize’ pistons and rings, and apart from the exhaust and pods, it’s all stock CB450. But I’ll probably swap the cranky, 47-year-old carbs out for a nice set of Mikuni VMs soon.”

The electrics were a big challenge. Cliff decided to build a brand new wiring harness from scratch, which he unusually describes as “fun.” Every electrical component on the bike is new, apart from the starter motor innards and the stator. The bike is running Dyna coils, a PAMCO electronic ignition and a tiny Antigravity 8-Cell Lithium Ion battery under the seat. The paint scheme is dead stock Black Bomber—even down to the chrome front and rear fenders being stripped back and painted silver.

Honda CB450
“Total project time was around 20 months,” Cliff reckons. “I did most of this work in my small garden shed, and some of the finishing off was done by a pro bike builder here in Melbourne.”

Cliff’s decided to call his CB450 the ‘Runcible Racer.’ “It comes from a café I saw called The Runcible Spoon,” he says.

“And since a runcible spoon is a sort of spoon but with extras, I decided the name would fit.”

The phrase ‘runcible spoon’ is usually credited to the 19th century poet Edward Lear. In the The Owl And The Pussycat, he wrote: “They dined on mince, and slices of quince,
 which they ate with a runcible spoon.
 And hand in hand, on the edge of the sand, 
they danced by the light of the moon …”