Building A Vet Rider's Dream Dual Sport - GasGas ES500 Bike Build

GasGas ES500 Dual Sport Project Bike

Story and Photos by Trevor Hunter

Stock bikes have come a heck of a long way in the last 20 years and more often than not, what you buy off the showroom floor is more than capable for your needs. This is more true than ever with off-road and dual-sport bikes as they are so much more performance oriented than before with a lot of ties and design ideas based off of competition bikes. However, dirt bike riders can never leave a bike stock and personalizing the machine to your liking and building up yopur dream bike can be just as much fun as riding the bike itself. This rings more true than ever with the dual-sport crowd as they often are a little bit older, have more expendable cash to spend on bikes and parts, and have the time to do it all. When Jay Clark gave us a call and asked if we’d like to test his GasGas ES500 dual-sport build with a wet SoCal desert landscape ahead of us, we couldn’t say yes fast enough.

The motor modifications are pretty straightforward and typical of what Jay does. FMF’s 4.1 Slip-On Muffler, A Twisted Development Vortex ECU and Exhaust Flange, and a Rekluse TorqDrive Clutch Pack and Slave Cylinder make up the bulk of the internal motor mods. Also, Jay removed the reed cage from the intake (Jimmy’s favorite mod!), pulled the charcoal canister out of the frame, and used a screen-less two-stroke air filter cage to prompt more airflow. The engine performance was solid. All of the mods worked well together and provided a clean, crisp running engine package from top to bottom. The RPM response and torque down low provided good grunt in the rocks and tighter singletrack before building into the mid-range and top-end where the bike came to life. Being a 500cc four-stroke, the engine and the bike itself found its legs in the more open, higher speed terrain. The bike was happy in gears 3-6 and with the stock gearing, we comfortably cruised down the asphalt and dirt roads at 65-70mph while maintaining a low RPM.

Race Tech’s suspension setup was cushy and comfortable for long miles on a bike and it did its job in the smaller bumps and rocks that you’d expect on a dual-sport ride. The 6500 kit forks and stock revalved shock offered a nice hand feel with good initial movement in the stroke and a supple feel in small bumps. As we progressed into the bigger bumps and whoops, the soft nature of the setting became more apparent but the bike remained straight and planted even when bottoming.

The new KTM and Husqvarna dual-sports come equipped with WP’s newer closed-cartridge spring forks and if this bike was equipped with those, Jay would have simply revalved the stock components. However, the GasGas model still utilizes the XPLOR fork and while we have had good luck in making them work well, Jay put some leftover WP 6500 kit forks on the bike.

The GasGas chassis is sporty and for what it is, is nimble and lighter feeling than its scale weight. It offered stability at speed and paired with the plush suspension, it provided a comfortable ride across the desert. The engine mods that liven up the engine help the lighterweight feel as the throttle response is playful and livens up the chassis as well. One of the big benefits of the Vortex ECU mapped by Twisted Development is being able to choose between ten different maps and find what works best for you. We say this all the time but power delivery affects more than just power, it really affects the entire bike’s performance. If a rider gels with the power delivery, it only helps the chassis feel and how well you can ride the bike. Likewise, if you struggle with the power delivery, you’ll be fighting the bike at all times. After starting the day in map one, we switched over to the second map that was loaded into the map switch and we much preferred that for its quicker revving, free feeling delivery over the chunky, classic four-stroke power that came from map one.

The overall cockpit is a bit more cramped than that of the KTM/Husky bikes, but most riders will find it just fine. The Seat Concepts comfort seat really works wonders when you’re sitting on the seat for any duration of time. The wide base and foam offers a lot of comfort and if you’re one that spends a lot of time sitting in the saddle, it’s a worthy investment. Some of the smallest little details that we typically wouldn’t see on a standard motocross or off-road bike build were some of the coolest details on Jay’s bike. For instance, the kickstand peg from Heimdale makes the new kickstand design from the Austrian group much more user-friendly on the trail. Likewise, the dual sport kit items from True North Moto cleaned up the instrument cluster and blinkers/taillight area tremendously for a sano package.

Of course, no bike is perfect, right? If I was to identify some things we’d change if it was my own personal bike, and this is purely personal preferance, I’d swap out the handguards and the grips. I’m not a huge fan of wraparound handguards so I’d use regular flag style handguards. Additionally, I prefer standard grips over lock-on grips so I’d go with ODI’s half-waffle grip and glue/safety wire the grips on. Aside from those two small details, it’s hard to find much fault in Jay’s setup. Everything works in unison and is a solid package from top to bottom.

Jay’s running a WP 6500 kit in the forks paired with KTM billet triple clamps with rubber mounted bar mounts.

This remote switch acts as a key and will prevent the bike from being able to start without pressing it. VERY clean.

This True North Moto cluster is compact and tight.

The Heimdale Kickstand Peg is a very nice touch and convenient on the trail.

Do You Like DBT Bringing You Fresh Content? Search and Shop Through the Links Below:

In Jay’s Words —

“Long time industry guy Jay Clark (DBTV) loves to ride moto and trail and with his now advancing age, he is looking to do more Dual-Sport riding. In many areas of our country, riding spots are going away and Street Legal Dual Sports will allow you to get to more fun rides in. Jay feels this new Generation KTM based Dual Sport is just the trick. After selling his older EXC bikes, he found some great deals from the Rocky Mountain Dealership in St.George, Utah with big rebates this past fall. It was time for Jay to build his ultimate trail worthy dream Dual Sport ride. So, he did it all.”