A fuel-injected uber-thumper from Brazil…
The Suzuki DR800S — also known as the “DR Big” or “Desert Express” — has been called the “Granddaddy of The Dual-Sports,” a 54-hp big-single beast born from a legendary Dakar desert-raider:
“The Suzuki DR Big was the production version of the bike ridden by Gaston Rahier in the Paris-Dakar rally in the late ’80s. After BMW refused to upgrade his R100GS, he jumped ship to Suzuki and did a big in-your-face by winning the next year on the DR.” —Allyn Hinton
Enter Renato Frateschi, founder of Brazil’s Frateschi Garage, whose early design inspiration stemmed from his passion for modern race bikes and circuit racing. Today, the shop offers a host of design and build services, including digital render, 3D modeling/printing, CNC, and more:
“Our business is to build motorcycles with design, balance, finish, style and taste.”
This ’96 Suzuki DR800 came from a client who originally wanted a scrambler with a GN250 tank, but Renato, upon assessing the lines of the bike, quickly proposed a flat track-inspired design. The donor had not run in years, so a full refurbishment was in order. Today, the only things left of the original donor are the engine, chassis, swing arm, and rear hub/caliper. The bike is now sitting on WP forks, an adjustable Sachs rear shock, and 19″/17″ wheels with Brembo brakes. The subframe was modified to fit the tracker-style tail and solo seat, and the exhaust is custom-built in stainless.
The bike was nearly ready to roll out of the shop when Renato proposed a new idea to the client:
“In the middle of the project we decided to take things a step further. Why not build a fuel injection system?“
That’s right, this DR800 tracker is now running a custom fuel injection system, built in-house using 3D printing, Arduino, and a smartphone app that displays velocity, rpm, GPS, fuel consumption, and allows the rider to choose and adjust different fuel maps in real time!
Below, we get the full story on this build straight from Frateschi, as well as more stunning shots from photographer Gustavo Epifanio (@gustavoepifanio).
Suzuki DR Big Tracker: In the Builder’s Words
This project came to us by our social networks. The owner of the 1996 Suzuki DR800 used to follow the garage Instagram account and admired our work. So, one day he showed up with the idea of converting the bike into a scrambler. At first, anyway, he wanted to put a Suzuki GN250 fuel tank on it. But taking a good look at the bike and its general lines like frame, height, and other details, I realized that the Intruder fuel tank would end up out of proportion.
I already had a flat tracker tail here. Looking at it I decided to propose a new approach and a new style, a flat tracker. The client had never heard of the style but gave me the green light to go on with the challenge to project a new design assumed by me.
The general conditions of the bike were not so good. The bike had everything in place, but many things were in awful condition. The engine was not working because the bike wasn’t used for many years. With this scenario, the first step was replace almost everything on the bike. The only thing that remained original was the engine, which received new spark plugs, new oil, filters, valves adjustments, a new paint job and a good and deep carburetor clean job. The exhaust system was remade in stainless steel and now ends in two exits on the same side.
All the original wheels, brake systems and suspensions were not used. What remained basically was the frame, engine, and the swing arm. Also, the rear caliper and wheel hub stayed. The front suspension now consists of an upside down 43mm WP with 230mm of travel. The rear suspension was replaced with an adjustable 215mm Sachs with easy access for the rider, even while in motion. By the way, the position of the rear sock was modified.
The front has received a BMW F800GS wheel hub. The wheels are aluminum 19×250 in the front and 17×350 in the rear. The brake system was replaced with Brembo systems and discs. The fuel tank was built, modifying an old one from a Honda CB400N. Finally, the end of the frame was modified to accommodate a single seat.
In the middle of the project we decided to take things a step further. Why not build a fuel injection system? I was studying the idea and spoke with the client. He liked it, and even with the bike technically ready to roll out, we decided to build from scratch a fuel injection system for it. So, we entered a second stage of the building work. And that for sure was the most difficult part of the whole project. I knew the basics to build a simple system. So, I took a deep breath and dove into the classes and books to build everything using 3D print, Arduino and even a smartphone app to control and remap everything when needed.
We put multi maps, Bluetooth control, lambda sensors and many other things. We printed in 3D a box to put all the electronics in only one place in the bike. Still talking about the electronics, we maintained the original CDI and the wiring harness and the ignition system as well. But all the lights were replaced by LED systems and the dashboard was replaced by a digital one with all the functions displays in one place. All placed under the rear fender.
The new ECU commands the fuel injection and is able to communicate with the app in the smartphone, displaying things like velocity, rpm, GPS, fuel consumption, and gives the possibility to choose and adjust many different fuel injection maps in real time.
The paint job was made with candy technic using a polyester base. The decals were made without embossment, with the paint itself using mask techniques. The seat is leather and some of the bike’s details were anodized yellow.
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Photos: Gustavo Epifanio (@gustavoepifanio)
I am very impressed with the engineering,especially regarding the fuel injection,3-D printing,etc.,but I’m hoping someone can tell me what “Arduino” is?