Welcome to a world where four-wheel drive meant a metal chain whirring between a front and rear gearbox, where suspension arms pivoted on exposed hinges, and where the scent of electric motor commingled with the faint tang of light oil on a roller chain. This book is about two legendary machines from the golden era of off-road radio control cars: the Kyosho Optima and the Yokomo 834B Dogfighter. These were not merely toys. They were the first serious mass-produced chain-driven 4WD buggies, and they changed the hobby forever. For a beginner today, discovering an Optima or a Dogfighter can feel like stumbling into a classic car garage filled with the smell of old leather and raw petrol. The shapes are familiar but the technology beneath the bodyshell is wonderfully alien.
If you have just acquired a re-release kit or are simply dreaming of owning one of these icons, this guide is written specifically for you. It is not a high-level racing manual nor a dry historical text. Instead, it is a practical, hands-on companion designed to help a newcomer understand exactly how a chain-drive 4WD buggy works, what makes it different from a modern shaft-driven or belt-driven car, and how to keep it running smoothly without fear or frustration. You do not need to be an experienced mechanic or a veteran racer to succeed here. You only need patience, a decent set of hex drivers, and the willingness to learn.
The Optima and the Dogfighter share a common mechanical soul: a central roller chain connecting two gearboxes. This chain gives them a distinctive whirring sound, a unique feel on the track, and a set of maintenance requirements that are entirely their own. Yet they are also deeply different machines, born from rival engineering philosophies. The Optima, with its bathtub chassis and coil-over shocks, feels more like a traditional buggy adapted to four-wheel drive. The Dogfighter, with its exposed frame, trailing arm rear suspension, and monoshock layout, is a more radical and quirky design. Throughout this book, you will learn to respect both, to troubleshoot their common failures, and to perform upgrades that modernize their reliability without destroying their vintage character.
We will cover everything from choosing a correct motor that will not shred your chain, to setting gear mesh on a sliding motor mount, to lubricating that chain correctly without attracting half the dirt on the track. You will learn why a slipper clutch is your best friend, how to adjust suspension, and which modern electronics fit without cutting up the chassis. There will be honest warnings as well as encouragement to embrace the quirks rather than fight them.
Most importantly, this book is written to be used. Keep it next to your workbench, smudge grease on the pages, and refer back to it every time you work on your car. By the time you finish reading, you will not only know how to upgrade and maintain your RE RE Optima or Dogfighter, you will understand why these cars still inspire such passion decades after they first raced across dirt tracks. So unplug your charger, clear your workspace, and let us begin the journey into the wonderfully mechanical world of chain-drive 4WD RC buggies. The whirr of a properly tuned chain is waiting for you.