Building The Big Twin Custom Beast

We build something old, something new, something bad, something blue

This article was originally published in the August-September 1997 issue of Cycle World’s Big Twin magazine.

When pondering what kind of one-off custom bike to build, the options are wide and sweet. How do you want to dance? Do you crave the waltz, holding hands gently with the innocent young lady next door, or do you want to leap, screaming at the top of your lungs, down into the nosh pit and get a little blood on your tattoo? To boogie or not to boogie. Pump it up, pump it up!

Last year, we created a bike that would be perfect for a ride to Sturgis, a dresser that was both stylish and functional (Big Twin, Fall, 1996 issue). This year, we would have something different.

Our first criterion was that it had to have a monster motor, something so strong it would rip the nuts off a pine tree just by riding past it. Our second requirement was that we wanted a simple, chopper-style terror. An outlaw. A wicked study in minimalism. Something with the clean, uncluttered and simple look of an old-style chopper, yet taking advantage of current technology. No bodywork or complicated, heavy looking schemes; we wanted brutal simplicity.

We got it.

When we asked Damon’s Custom Creations of Brea, California, to build our chopper, owners Tom Prewitt and Richard Perez enthusiastically accepted the challenge. It only took a couple hours of discussion for all of us to iron out a basic game plan, after which Prewitt and Perez went to work like a couple of whirling dervishes.

Big twin custom bike

“Our first criterion was that it had to have a monster motor, something so strong it would rip the nuts off a pine tree just by riding past it. Our second requirement was that we wanted a simple, chopper-style terror. An outlaw.”

Kirk Willis

For propulsion in our retro-cruiser, we selected S&S’s new, 113-inch Super Side­winder, a powerplant that fits the monster-motor description to a Vee (see “S&S 113-cubic-inch Super Sidewinder,” pg. 32). The motor arrives disassembled, but, says Prewitt, “As far as kit motors go, it was a very good one. It was a lot easier to put together than comparable motors and would be especially nice for someone who doesn’t have the equipment or knowledge to custom-build an engine.”

Damon’s mechanic, John Hart, who actually assembled the Super Sidewinder, agreed with Prewitt. “It went together just like any regular 98-inch motor,” says Hart, who is used to working on lots of other big, muscled engines. “It’s not often that I’m im­pressed with something brand-new. There usually are bugs that need to be worked out, but not with this engine.”

After the motor issue was decided, the next question was, how does the power get to the transmission? “We were going for the chopper look,” says Prewitt, “so I looked at a lot of different belt drives on the market. We decided on the Primo drive because of the new technology of the belts. Also, the motor plate they have is the strongest on the market. It’s a three-inch-wide belt system with a one-inch motor plate on it.

“There are a lot of advantages with the Primo setup. Number One, you have the cushioning effect of a belt, which cuts down on vibration in the motorcycle, and Number Two, they seem to start easier. Primo has developed a different gear ratio where the starter gear mates to the clutch basket, and it allows big-inch motors to start with less effort.

Primo primary drive

The Primo primary drive system with its exposed belt sets the tone and shouts CHOPPER louder than any other component.

Kirk Willis

“The Number Three advantage of using Primo’s setup,” continued Prewitt, “is that they have developed a new-style clutch. It has more surface area on the clutch plates themselves and utilizes a diaphragm-type spring. So, all around, it makes a good package.” The decision to leave the primary semi-exposed was another nod to the chopper look we were after.

Still, the most radical aspect of the 1997 edition of the Big Twin Custom is the frame. To make all that power usable in a chopper, Prewitt and Perez decided that the new series of frames from Pro-One would best handle the job. “Softails have been done to death,” says Prewitt, “so we were looking for a different type of suspension. The standard chopper from the old days would have been a hardtail; but everybody knows that unless you have buns of steel, you’re not going to ride a hardtail very far. So we looked for a different type of suspension and ended up with the Pro-One frame for a couple of reasons.

“First, it’s designed to have some suspension travel left during hard acceleration so it can handle a lot of horsepower; it’s actually meant for a big-inch motor. Second, it’s got Pro-One’s Quad-Link suspension in the rear, just like in a lot of race cars. This suspension makes the bike more livable either on the street or the quarter-mile—whatever you want to do. The Quad-Link system keeps the rear end and all the drive components in line with one another. It can’t twist; it can only go straight up-and-down.”

big twin custom details

Pro-One frame with Pro-One Quad-Link suspension, modified Sportster tank and all of the chrome goodness make this chopper shine.

Kirk Willis

Unlike the motor, which came together and worked seamlessly, the Pro-One frame (manufactured by Daytec) is brand-new and needed some tweaking, especially to achieve our goal of attaining the chopper look. As such, the chassis needed to be lowered more than the frame designers intended. That entailed a bit of added work for the crew at Damon’s, but after all, the trademark of the hardtails was that butt-on-the-ground look.

To further portray the chopper theme, a modified Sportster tank was chosen—partly because it looks cool, and partly because it was the tank of choice for a lot of customizers in the Sixties. They’d throw the stock tanks in the dumpster and prop the little peanut tank up on the Big Twin’s long, long backbone. But because Sportster tanks were really small, the space between the front of the tank and the neck, as well as the back of the tank and the seat, was so great that the tank often looked like a snail sitting in the middle of an empty clothesline. To give the Big Twin custom’s tank a tidier fit, Damon’s widened the Sportster unit six inches and lengthened it another six. As a touch of nostalgia, two gas filler holes and caps were installed for a Fat Bob look.

With the Big Twin bike taking on its own distinct shape, Prewitt and Perez decided that the fenders would have to be one-off pieces designed to work on this machine. To that end, they had fenders custom-made by metal maestro Jesse James.

As always, the final touch was paint—and, in the case of this bike, the big decision of whether to flame or not to flame. Because last year’s Big Twin custom was so flame-intensive, we decided that this bike would take another route. Thus, Perez and Damon’s resident painter, Luis Alvarado, created the flowing graphics seen here. Alvarado applied both the background color and the graphics.

big twin custom engine

“It’s not often that I’m impressed with something brand-new. There usually are bugs that need to be worked out, but not with this engine.”

Kirk Willis

There always are nits and fits encountered with assembling an original custom; but with the Big Twin Custom II, those problems were compounded by the compressed time-frame in which the builders had to work. We contracted with Damon’s to build this machine very late in the grand schedule of H-D-related activities; before we knew it, Daytona—where we were committed to debut the new custom—was right around the corner. So, the all-nighter workathons began. Mechanic Mike Weber of Damon’s devoted every waking hour to bringing the big blue custom to life, and the bike went from bare, unwelded metal to the essential machine you see here in just six days! That includes assembly, painting, layers of clear coat, sanding and all the details associated with the appearance of the bike. Yet sitting in the Big Twin booth at the Ocean Center in Daytona Beach during Bike Week, the custom looked glorious.

Unfortunately, it didn’t run; there hadn’t been enough time for that. Just getting the bike to Daytona meant merely dropping the engine in the frame and making it look completed but not properly plumbing, servicing and tuning it.

So, after we brought the bike back from Daytona, it was disassembled and the fitting and rigging began. “Our normal procedure on a from-the-ground-up custom is to pre-assemble the bike, check it, and then ride it a hundred miles or so,” says Prewitt. “At that point, you can find out if anything is rubbing or dragging before any paint or chrome can be damaged. When you’re sure everything works properly, then you disassemble it, do any necessary modifications, paint it, chrome it, and then put it all back together.” But, due to the heavy show schedule planned for the bike, along with a severe shortage of time, that process wasn’t possible.

Because of those circumstances, the final payoff of months of work and anticipation hadn’t yet occurred: The bike could not be started and ridden. But don’t worry in our next issue, we’ll give you all the gory details about what it’s like to ride a bad-ass, 113-inch, modern-day chopper.

Stay tuned for Part 2: We’ll call it “Taming the Beast.”