The Suzuki RE5, a bold experiment from the 1970s, promised a revolution in motorcycle engineering with its rotary engine. However, this ambition came with a price. The RE5, while innovative, was plagued by a number of issues that ultimately contributed to its short production run and its status as a cautionary tale in motorcycle history. These weren't just minor quirks; they were significant problems that impacted reliability, performance, and even safety, making owning and maintaining an RE5 a considerable challenge.

So, What Exactly Went Wrong with the Rotary Dream?

The RE5's woes weren't rooted in a single design flaw but rather a confluence of factors, starting with the engine itself. The rotary engine, while theoretically offering smooth power delivery and fewer moving parts, presented significant hurdles in practice, particularly at the time.

Sealing Issues: The Wankel rotary engine relies heavily on the apex seals, which seal the combustion chambers formed between the rotor and the epitrochoidal housing. The RE5 suffered from excessive apex seal wear, leading to compression loss, reduced power, and difficult starting, especially in cold weather. These seals were not particularly durable in the RE5's design, and finding replacements today can be difficult and expensive. Early models were particularly susceptible to this problem.

Overheating: The rotary engine generates a lot of heat, and the RE5's cooling system wasn't always up to the task. Overheating was a common complaint, especially during slow-speed riding or in hot climates. This could lead to engine damage and further exacerbate apex seal wear. The cooling system design was simply inadequate for the engine's heat output under certain conditions.

Fuel Consumption: Rotary engines are notorious for their poor fuel economy, and the RE5 was no exception. Its fuel consumption was significantly worse than comparable piston-engined motorcycles of the time. This was a major drawback at a time when fuel prices were rising, and it made the RE5 less appealing to potential buyers. The complex carburetor system didn't help matters, either.

Complex Carburetion: The RE5 used a Mikuni carburetor system that was incredibly complex, featuring multiple jets and circuits designed to optimize fuel delivery across the engine's RPM range. However, this complexity made the system difficult to tune and maintain. Any slight deviation from the factory settings could result in poor performance, stalling, and even engine damage. Many owners found themselves struggling to keep the carburetors properly synchronized and adjusted.

But It Wasn't Just the Engine… The RE5's Other Troubles

While the rotary engine was the primary source of problems, the RE5 also suffered from issues related to other components and design choices.

Electrical System Woes: The RE5's electrical system was notoriously unreliable. Problems with the charging system, ignition system, and wiring harness were common. This could lead to a variety of issues, from a dead battery to complete engine failure. The electrical components were simply not robust enough to withstand the demands placed on them, and the wiring harness was prone to corrosion and shorts.

Starting Difficulties: Combining the apex seal issues with the complex carburetion and the temperamental electrical system, starting the RE5 could be a real ordeal, especially when cold. Owners often resorted to elaborate starting procedures, and even then, success wasn't guaranteed. This made the bike less practical for everyday use.

Weight and Handling: The RE5 was a heavy motorcycle, which negatively impacted its handling. It felt cumbersome and difficult to maneuver, especially at low speeds. This was partly due to the weight of the rotary engine and the robust frame needed to support it. The weight distribution also contributed to the bike's less-than-stellar handling characteristics.

Limited Parts Availability: Because the RE5 was only produced for a short time, and in relatively small numbers, parts availability has always been a challenge. Finding replacement parts, especially engine components like apex seals, can be difficult and expensive. This makes owning and maintaining an RE5 a long-term commitment that requires significant research and resourcefulness.

The Design That Divided Opinion

Even the RE5's distinctive styling contributed to its downfall. While some appreciated its futuristic look, others found it unattractive.

The "Rotary Toaster" Instrument Cluster: The most controversial design element was undoubtedly the instrument cluster, which was housed in a large, cylindrical housing often referred to as the "rotary toaster." While the design was unique, many found it bulky and visually unappealing. It also obscured the rider's view of the road.

Overall Styling: The RE5's overall styling was polarizing. Its large fuel tank, long wheelbase, and unusual proportions didn't appeal to everyone. While Suzuki was trying to create a futuristic and distinctive motorcycle, the design ultimately proved to be a barrier to sales.

What About the Different Models? Did Some Fare Better?

Suzuki made some modifications to the RE5 during its short production run, but these changes didn't completely address the underlying problems.

The M Model: The "M" model, introduced in 1975, featured a redesigned instrument cluster, a smaller fuel tank, and other cosmetic changes. While these changes improved the bike's appearance, they didn't significantly improve its reliability or performance. The M model still suffered from the same fundamental problems as the earlier models.

Minor Mechanical Tweaks: Suzuki made some minor mechanical tweaks to the RE5 over time, such as improvements to the cooling system and the carburetor settings. However, these changes were not enough to overcome the engine's inherent limitations. The apex seal issue, in particular, remained a persistent problem.

So, Why Did Suzuki Even Try a Rotary Engine?

Despite its problems, the RE5 represented a bold attempt to innovate and push the boundaries of motorcycle technology.

The Promise of Smooth Power: The rotary engine offered the potential for smooth, vibration-free power delivery, which was a major selling point. This was seen as a way to improve rider comfort and reduce fatigue. The theory was sound, but the execution fell short.

Fewer Moving Parts: The rotary engine has significantly fewer moving parts than a traditional piston engine, which theoretically meant greater reliability and easier maintenance. However, the RE5's apex seal issues negated this advantage.

A Competitive Edge: Suzuki hoped that the rotary engine would give them a competitive edge in the motorcycle market. They wanted to be seen as an innovative and forward-thinking company. However, the RE5's problems ultimately damaged Suzuki's reputation.

Is the RE5 Worth Owning Today?

That's a complicated question. The RE5 is undoubtedly a unique and historically significant motorcycle. However, owning one requires a significant investment of time, money, and effort.

A Labor of Love: Owning an RE5 is truly a labor of love. It requires a deep understanding of the bike's quirks and a willingness to tackle complex repairs. Parts are difficult to find, and qualified mechanics are even rarer.

A Collector's Item: The RE5 is primarily a collector's item. Its value is based on its rarity and historical significance, rather than its performance or practicality. If you're looking for a reliable and easy-to-maintain motorcycle, the RE5 is not the right choice.

A Rewarding Challenge: For some, the challenge of owning and maintaining an RE5 is part of its appeal. It's a chance to work on a truly unique and innovative machine and to preserve a piece of motorcycle history.

Frequently Asked Questions

  • Why did the RE5 fail? The RE5 suffered from a combination of factors, including engine issues (apex seals, overheating), a complex carburetor system, electrical problems, and polarizing styling.

  • Are RE5 parts hard to find? Yes, parts availability is a major challenge for RE5 owners. The bike was only produced for a short time, and many parts are now rare and expensive.

  • Is the RE5 reliable? No, the RE5 is not known for its reliability. It requires frequent maintenance and is prone to breakdowns.

  • What is the "rotary toaster"? The "rotary toaster" is the nickname given to the RE5's distinctive instrument cluster, which was housed in a large, cylindrical housing.

  • Is the RE5 worth restoring? That depends on your resources and passion. Restoring an RE5 can be a rewarding experience, but it's also a costly and time-consuming undertaking.

The Rotary's Legacy

The Suzuki RE5, despite its shortcomings, remains a fascinating chapter in motorcycle history. It's a testament to the ambition and ingenuity of engineers who dared to challenge conventional wisdom. While the RE5 ultimately failed to live up to its promise, it paved the way for future rotary engine development and serves as a reminder that innovation often comes with its share of challenges. If you are considering purchasing one, be prepared for a long-term commitment to maintain and repair this unique machine.