The 2020 Dirtbag Challenge, or why you should immediately build a cheap chopper

And then, there I was, seven hours before the start of the 2020 Dirtbag Challenge, staring at the jumbled mess that was the TIG-welded repair of a damaged engine case, the desperate last-minute attempt to fix a dribbling oil leak on my entry. My build partner and I had spent two months getting the project — a 1998 Suzuki DR650 we called "Catfish," because it got stuck on the bottom of a river — ready and had just got it running properly an hour before. Now this final setback. Maybe it was time to quit.

I mean, what was I thinking, anyway?

What's the Dirtbag Challenge?

In the early 2000s, Dirtbag Challenge founder Poll Brown, a garrulous Royal Army veteran, was BS-ing with his mates. They were tired of watching celebrity chopper builders on TV as they built “cheesy, high-buck customs” for wealthy folk who likely didn’t do much (if any) riding.

“Oi!” Poll (probably) said. “We should have a chopper-building contest where you can’t spend more than $1,000, have to finish in 30 days... and no Harleys!”

Does Poll hate Harleys? Not at all. In fact, he owns two. He only worried that a Harley, with its iconic looks and sounds, would have too great an advantage over other brands, leading to a Harley-only contest. His mates said “Yeah!” and the first Dirtbag Challenge was on.

As word of the event spread, curious “lookey-loos” started showing up to watch the awards ceremony, which turned into a happening, complete with the usual Bs of biker parties: Beer, BBQ and Bands. Which of course led to additional Bs like Burnouts and Bandages. All the noise, smoke and drunken naughtiness was confined to a particularly grungy and un-gentrified corner of San Francisco, so the authorities never seemed to care, at least not until the event got too big to ignore. In recent years, it’s been held in Oakland, where craziness is more tolerated.

A few years into the ride, Poll noticed the entries were getting more elaborate, sillier and less ride-able, so he added a riding component to the event. At first it was just 50 miles, but since then it has grown to a multi-day tour going several hundred miles or more. Some of the entries have been magnificent. For the last few years, Poll decided to allow a $2,000 budget and two months build time. Inflation.

And then: COVID-19. Rather than call off the event, Poll decided to make it smaller, with no public awards ceremony. As a result, just nine entries arrived at the start line in San Francisco, and eight finished the three-day fracas. The event was almost scrubbed at the last minute, thanks to Northern California’s new role as wildfire capital of the world, but a generous friend offered his farm for an overnight campsite.

The ride ended on several miles of bumpy dirt road to the Usal Beach campground, 214 miles from the start point. There, a Unimog was set up as a DJ stage and the party commenced, with some of the Bs represented, culminating in an award ceremony. The next day, the participants found their own ways home.

Poll, of course, enjoyed himself, as he always does.

The DBC “is all about the yucks," he said. "Some of these so-called biker events take themselves so seriously. They've got their vests on, they’ve got their faces on.”

Dirtbags are just there for fun... and the love of building crazy bikes.

So who are these dirtbags? And what do they build? Let's take a closer look at a few entries.

Justin Martens' turbo Yamaha FJ600

All kinds of people — mechanics, college students, moms, graphic designers, tow-truck drivers, bookkeepers — participate in the Dirtbag Challenge, but the most common profile is a young-ish male suffused with usually home-grown engineering, mechanical and fabrication skills. Slather all that with a generous coat of self-effacing whimsy.

That’s Justin Martens in a nutshell. At 35 years old, Martens — who works for the Marin County Public Works Department, just north of San Francisco — has been participating in the DBC since 2014. He offered me a test ride on an early entry, an ancient KTM two-stroke hardtail chopper that barely finished the 50-mile route required back then. The bike didn’t run for me (probably for the best), but its crude charm and “WTF!” attitude spoke to Justin's potential as a builder.

He built a couple more choppers and then built a stunning Supermoto around an old Yamaha XS650 motor. It took the “Coolest” award in the 2018 DBC and then went on to be displayed at the Los Angeles One Moto event. So for 2020, he knew he’d have to do something to top his past achievements.

“I heard Matt (see below) was building a turbo, so I wanted to build a turbo,” Justin said. After much consultation with a friend who’s into Mazda turbos and some online research, he realized his old Yamaha FJ600 would probably work well with a turbo setup like the 1983 Seca Turbo, which used a similar engine and carbs.

eBay was a handy font of parts here, as a Chinese-made turbocharger can be had for less than the cost of a fancy meal and a used-parts search for “Seca Turbo” yields a couple thousand results. A surge tank (What’s that, you say? I don’t know either.) was $12, and some other bits got tossed into his shopping cart as well. Once all the components were located, it all just sort of came together, much to the chagrin of his buddies, who were expecting him to get mired in such a tricky project.

“It went together smoothly, even though the common wisdom is you should never turbo anything with more than 10:1 compression,” he said.

Topped off with his custom fairing and other Dirtbaggy touches, he was surprised at how well it ran. It held its own against a turbo’ed Suzuki Bandit 1200 built for a prior Challenge by Jason Pate, completing the 500-mile ride with minimal problems. He estimates it makes 90 horsepower, which is what Yamaha rated the original Seca Turbo for. Its flaw? Riding on the dirt portion to the campsite on the second day revealed that turbocharged fours don’t make good dirt bikes.

Will he be back next year?

“Yes,” he told me. “I have to. It’s a blast.”

Matt Rietz's Volkswagen turbo-diesel

If you work at a dealership repairing a certain brand of European car that’s not known for reliability, you’ll probably have a) a lot of great diagnostic and mechanical skills, and b) an expanded sense of possible engineering solutions. That sounds like San Jose, California-based Matt Rietz.

Like Justin, Matt has participated in many DBCs — this is his sixth consecutive event. Also like Justin, his first build, an elderly Yamaha DT175 two-smoker that seized after being pushed too many miles at its blazin’ 55 mph top speed, wasn’t propitious. Also like Justin, Matt knew he needed to “go big.” In Matt’s case, he’s getting married next year, so he’ll have to skip the next DBC, so he needed to do something special. A special motor… maybe a diesel. But what kind of diesel?

“Someone at work had a 1981 Rabbit diesel pickup they wanted to get rid of," Matt said. "The guy tried to put in a stereo, and there was a fire.”

That’s actually a good thing, as it tells you the truck was likely running. Because who puts a stereo in a non-runner? (Answer: Someone from Santa Cruz.) But what about fire damage to the delicate electrics? Also not a problem. “It really only needs one wire,” Matt said. Aside from the alternator and fuel-cut solenoid (again, I don’t know what that is) there just aren’t a lot of electrics on a diesel.

There’s also not a lot of power. That ancient VW diesel motor made all of about 50 horses (but enough torque for a small pickup truck), not much for what would be a 900-pound motorcycle. Can you guess the solution? Yes, a turbo, but how? Luckily, VW offered an “ECOdiesel” Jetta for the U.S. market in 1991 and ’92 which used a turbocharged version of that old 1.6-liter mess from the '70s. Even though fewer than 800 of these cars were sold here, Matt found a turbocharger and could proceed with the rest of the project.

A Honda CX500 provided the headstock, frame backbone and most importantly, the VIN. The front end (except the Suzuki SV650 wheel) is from a Yamaha YZ450 (perfect for a half-ton motorcycle), and the rest he made from scratch, stuff he “had laying around.” The big sheet-metal box holds the battery, a gas tank and some storage (he doesn’t like tank bags). The rear differential is from an Audi TT and the rear suspension is, to use a Poll Brown-ism, yer mom. Oh, and that’s a big, fat car tire back there. Again, yer mom.

The biggest technical challenge? Getting the rear differential to work.

“I had to make it up and figure it out on my own," Matt said. "I don’t have formal training in engineering.” What about getting technical help? “I didn't know anybody who could really help me." What? You don’t know anybody who turned a VW pickup truck into a motorcycle?

Still, like any good American, he got ‘er done. The bike runs well enough, though he thinks the turbo doesn’t really add much power.

“It makes cool sounds... and that's about it,” he admitted.

Total expense: $1,191, with the most money sunk into the motor.

Unsurprisingly, it’s sort of a handful on the road, especially at lower speeds. In fact, Matt almost had to end early because of the bike’s stiff and jerky foot clutch. Waiting to pull out of the driveway at the event’s start in San Francisco (after riding that morning up from San Jose), the bike sort of… got away from him as he started out, trying to feather the clutch with the handlebar turned. Avoiding another bike, the chopper went into a wobble and Matt hit a truck, breaking his hand. The rest of the ride left him behind.

Matt wasn’t giving up. He wrapped his hand, fixed the broken alternator belt, unbent a few things and headed north. He caught up by dinnertime and completed the 500-mile ride.

"I rode behind him,” Poll told me. “I don't know how he made it.”

At least the bike is very stable in a straight line, so he could rest his hand on the boring parts.

Would he do a build like that again? Likely not. Building such a bike is “a horrible idea," Matt said. "Heavy, no power, it just doesn't make any sense.”

I think the universe is richer because somebody did it, and Matt had a lot of fun. “I was struggling for months, near death for two days on the ride, but the experience makes everything else seem less challenging," Matt said. "It's just a blast.”

Alan Lapp's Unitard trailer

And now for those of us who didn’t finish. Alan Lapp is a graphic designer, motorcycle instructor, former roadracer and experienced Dirtbagger who, in 2015, built a machine so different and radical we just call it “oddbike.” With a Suzuki DR650 motor and innovative chassis completely built in Al’s basement workshop, it defies description and knocked out judges and spectators alike, and also got paraded at the One show. He wasn’t able to make the next few DBCs, so for 2020 he wanted to do something really different.

One thing Al likes when camping is comfort, so he wanted extra storage for his big old 70,000-mile Suzuki V-Strom. It already has a top box, and he likes to lane-split through California traffic, so he’s done with side cases. A trailer? Well, moto-trailers can be pretty wide, but what if he were to take this long, casket-shaped Yakima car top box a friend abandoned and put it on a long, single-wheeled trailer, with a Honda CRF450 swingarm and an old Suzuki GSX-R rear wheel someone left on the sidewalk near his house in Oakland?

"No Al!" I said. "Don’t!"

Al knows what he can and can’t do, so he ignored me and did it. Like much of what this self-taught machinist and welder creates, the solutions are raw, yet elegant. The long trellis frame mates to the swingarm with homemade bronze bushings and an adjustable scooter monoshock. And the bi-axial universal joint that joins sturdily to the back of the V-Strom (using the centerstand and luggage mounts) is quite a thing.

I was in Al’s shop working on my own project the entire time he worked on his, and he built it quickly. Al can see something in his head and then just cut, bend, drill, lathe and weld it into reality. The only thing he bought, aside from some steel tubing, was a glowing, remote-controlled Chinese-made flagpole disco light that looked too much like an adult novelty for my comfort. Seeing him cackle with glee as he bolted it to the back of the trailer made the whole thing worth it.

Unfortunately, the tight build schedule made extended debugging impossible. Right away, he noticed low-speed, small-radius U-turns were difficult, if not impossible, as the trailer would fall over and then want to lever the bike into a slow-motion highside. Al rode the event anyway, and though the rig handled great at higher speeds — not a wobble or weave to report — a low-speed panic stop on the first evening avoiding a stop sign runner pitched Al off the bike, pinning his foot under the Strom and sending him home. As we used to say, “That’s racing.”

Next year? “Chopper with a trailer, Gabe.”

Nooooooooooo!

My DR650 hipster-sumo

I can do more mechanical work than most riders, but modding stuff too much makes me queasy. I didn’t even know how to properly splice wiring. So although I’ve known about and covered the Dirtbag since its inception, I never seriously considered building a bike.

And then I started noticing custom bikes on the hipster custom-bike sites (you know the ones) and started falling in love with retro-hip scramblers and supermotos. The thought of a single-cylinder supermoto or scrambler with retro looks and modern reliability appealed to both my romantic and practical sides. And knowing that Al built an entire motorcycle made it seem not so daunting.

At first I thought Al would want to build such a machine for the DBC, and suggested he do so, using the DR650 motor from the Oddbike. But as we emailed and texted back and forth, it became clear this would be my bike, and it would be awesome, and it would fall well within the $2,000 limit. How hard could it be?

If it weren’t for Al, impossible. His expertise in design, welding, engineering and all manner of metal fabrication made pretty much anything you could do to a DR650 possible. We came up with a rough design and after much debate we decided to use 17-inch wheels, stock frame and suspension, a homemade subframe, the aluminum tank from a 1970s Yamaha TT500 and a Chinese-made eBay seat. The exhaust would be an old piece of junk 1980s aftermarket can mated to the stock headers.

Oh, and I’d have to rebuild the motor, as the transmission had been incorrectly reassembled and it wouldn’t shift into fourth.

Sounds like a big list, right? Well, thanks to Al (again), we were able to get all this done by the Wednesday before the Friday deadline. Unfortunately, the bike wouldn’t run right — electrics! They get you every time. The lithium battery, even though it was putting out more juice than the stock size, just couldn’t turn the bike over more than once or twice, and the bike would die intermittently in first gear, even after I disabled the sidestand interlock silliness.

Fast forward to past midnight on Friday morning. Al points out that I had connected the main ground to the starter relay, and the relay-to-starter wire to the battery, which meant a small single-wire ground was going to the wrong spot, which produced the weird electrical gremlins. Once corrected, the bike ran like a Swiss top, if that’s a thing. I tore off to do a short freeway test ride, stopped to fill the absurd two-gallon tank and went back to help Al finish the UniTard. As we were zip-tying the trailer’s wiring harness I saw a big dark stain…under my bike. A gouge in the case under an oil fitting, repaired with Hondabond and fervent hope, was dribbling oil. We spent an hour attempting to TIG weld a repair until, at 2:20 a.m., I decided to call it quits so Al could finish his project and get some sleep before the ride.

I know, I know, we could have worked through the wee hours and made the ride, but you know what? I’m 51. F**k it!

Next year.

2020 Dirtbag Challenge winners

"Matt walked away with most of the awards" said Poll. Matt Reitz’s thing-that-has-no-name wound up "easily" with the coveted “Sketchiest” award (which needs no explanation), the “Jake” award (which goes to the bike that really shouldn’t have finished, but did anyway) and Poll’s “Founder’s Choice” award.

“I can’t believe he did that,” Poll told me, referring to Matt’s miraculous recovery and finish, and Poll has seen some unbelievable things over the years. Things that would make Alan Cathcart’s head f**king explode.

Other winners:

• Coolest: Kyle Cannon’s Kawasaki Vulcan 800 rigid chopper
• Cleverest: Julian Farnum’s undisclosed motor with custom frame
• Prettiest: Steve Firmen’s Honda XL500 hardtail bobber
• Gulu (craziest): Paul Astier's Suzuki GS550, which Poll claimed "somehow rode up a tree"

The future of the Dirtbag Challenge

Will there be a next year? Absolutely. Poll is in it for the long haul. He’s not in it for money or fame. He doesn’t make money off it – “it costs us money,” he claims. It’s more of an annual thank-you party for Bay Area motorcyclists, real riders who love riding, wrenching, going fast, getting dirty and making their dreams happen.

If you’re getting a sausage-party vibe here, that’s just because no women entered this year. Other years, though, there has been more female participation, and Poll loves to see it. Women bring a different energy and perspective everybody enjoys. The highly recommended low-budget documentary Dirtbag (directed by DBC photographer Paolo Asuncion; and there’s a follow-up, Dirtbag II, Return of the Rattler) follows an all-women team of builders in a past challenge, and I’m sure we’ll see more female participation in future DBCs.

So what is a Dirtbag anyway, I asked?

"Somebody that has determination and is willing to put in the energy to fulfill their own dreams and ideals regardless of how difficult or challenging that might be,” said Poll. “It's not called the Dirtbag Easy.”

Sound like a great event? It is. Should you do it? Yes. Not only should you do it, you should start your own custom-build event.

“Go ahead and do it,” says Poll. You can’t call your event a Dirtbag Challenge, but if you send him a message he'll share his guidelines with you to help you get started.

Make it happen! Like Poll told me as we wound up our interview, “Dreams aren’t made on the couch.” See you there.