What Were Rotary Engine Motorcycles And Why Are They Not Used?
Whilst there are plenty of obvious differences between cars and motorbikes, something that becomes extremely clear when someone with a full car driving licence heads to a motorcycle driving school is just how fundamental these differences are.
It is not just the case that motorbikes have two fewer wheels, but that on a fundamental design and engineering basis cars and bikes are worlds apart.
This is often easiest to see when engineering decisions that work with cars and other vehicles are tried with motorbikes, with unusual results, to say the least.
One of the most notable examples of this was the extremely rare trend of the Wankel-engined motorbike and the somewhat infamous Suzuki RE5.
A Wankel rotary engine was at one point quite a popular type of engine for sports cars, as whilst it was unusually designed it was remarkably powerful for its size, although this typically came at the expense of low fuel economy.
It was most famously used by Mazda in sports cars such as the RX-8 but the concept seemed tailor-made for motorbikes, as the perfect engine would be light, smooth and tiny, with an exceptional power-to-weight ratio.
In the 1970s it was seen as the future, but ultimately very few Wankel-engined bikes were ever produced, the most infamous of which was Suzuki’s attempt in 1974, after two years of fraught development and testing.
Part of the problem was that whilst the engine itself was light and simple with its single rotary
system, the RE5 had an exceptionally complex engine to manage the extreme heat that the Wankel engine generated. This included both an oil-cooling and liquid-cooling system, as well as no less than three oil systems.
The complexity added a lot of weight, made it extremely unreliable and prone to failing after just a year, and when it did it ironically proved to be quite an expensive fix due to the fact in most instances the entire engine system needed to be replaced.
It only lasted two years on the market, and other proposed Wankel motorcycles were cancelled or discontinued as well.
