Building a custom bike

The gritty work: pounding, cutting and grinding

Story by Bill Kresnak
Photos by Bill Andrews

Skunkworx Custom Cycle owner and bike builder extraordinaire Bruce Mullins, and master bike builder Jim Davis, stand silently staring at the mockup of their latest creation: a long and low custom bike.

The project has entered a critical stage: the fabrication and welding work.

The Columbus, Ohio, team decided what it wanted to build, ordered parts like the frame, motor, and blank fenders, and assembled as much as possible to make sure everything fit and to see where mounting brackets need to be welded on.

Now, Mullins and Davis are figuring out what they need to do to get the long and lean look they want, which will involve fabricating the oil tank, side panels, a chin fairing, and more.

Just to complete the sheet metal work and welding will take more than a week, so the duo wants to be sure they have every piece thought out before the work begins.

The Skunkworx team mounts the wheels, and makes measurements in thousands of an inch to be sure the brake calipers line up properly.

Then, they cut templates out of poster board, and begin cutting, pounding and grinding sheet metal. The bike is starting to take its final form.

To help get the long and low look they're looking for, Mullins and Davis want the fenders to really hug the tires. But that also poses a challenge.

"That's the hard part about making a softtail chopper with a welded-on rear fender," Mullins says. "Getting the fender to hug the tire. We use an air shock so you can drop it down to show, then pump it up to ride."

While working on supports for the rear fender, Mullins asks his crew to remove the rear wheel to avoid damaging it while he cuts and welds. They run into a design problem.

Because the bike has a single-sided swingarm and the fender is hugging the rear tire, the tire and wheel won't clear the fender for removal.

On a normal rear end, you could simply pull out the axle and drop the wheel straight down. But with the single-sided swingarm, you need to pull the wheel sideways off the hub, like on a car.

Mullins gives it some thought and decides on a redesign of the fender support, which requires cutting more sheet metal.

"In this case, function dictated the new design," Mullins says.

Making metal perform The oil tank cover
		Mullins and Davis discus the pattern for the oil tank cover (top left). They tape the pattern into place to see how it'll look (lower left). It is a painstaking process of mocking up, discussion and redesign.
		Once they've made their decision, they cut out the sheet metal, (left) bend and pound it into shape (center), then tack weld it onto the bike before the final weld (above).
The fender supports
	Davis cuts fender supports out of 1/16-inch sheet metal (left). Mullins then marks approximately where the bend should be in the piece (above). He then bends the piece by hand (right).
Mullins aligns the support (above) before he tack welds it into place (center). Final adjustments are handled via hammer (right).
The fender
Mullins masks out what needs to be trimmed from the rear fender (top three).	Once the masking is done, Davis and Mullins take turns cutting and grinding away the excess. (lower three)
The build thus far
Most of the components are on the bike including the custom tank and handlebars.	The rear fender is added and masked off.	The frame is stripped bare for the final welding. The power train will be installed and removed many times during the build so the team can see how everything fits together.

Following the build:

• Part nine: Cherry Bomb hits the show circuit

• Part eight: Finished—now on to the show circuit

• Part seven: Sleepless nights

• Part six: The beginning of controversy: the paint

• Part five: The bike takes shape

• Part four: The gritty work: pounding, cutting and grinding

• Part three: The vision unfolds

• Part two: How custom can your bike be?
  How much money do you have?

• Part one: Building a custom street rod: Skunkworx