Honda Files Patent for Supercharged Africa Twin

[Advpulse]

Photo by Honda

Honda’s redesigned CRF1100L Africa Twin made big strides when it hit the market in 2020 thanks to a raft of upgrades to its componentry, a more-powerful parallel-twin engine and more-compact chassis, as well as a much-appreciated reduction in weight, however slight. 

And judging by recently-published engineering patents describing a supercharged Africa Twin, the R&D team at Honda Japan isn’t finished with its attempt to stand out in the adventure liter-class. Keeping that in mind, a supercharged AT, while seemingly extravagant, makes real sense, seeing how it currently lacks peak power when compared to adventure riding’s top-shelf contenders, like the KTM 1290 Super Adventure offering 160 horsepower and BMW’s big GS pounding out 136 ponies, compared to the Honda’s 101. 

In fact, incorporating the supercharger portrayed in these schematics, a positive displacement design like those used on drag bikes to focus increases on low to mid-range grunt — the kind of power most advantageous for off-road riding — would be a win-win for the consumer. In addition to adding far more horsepower and torque, patents appear to indicate there would be little changes to the chassis and weight gain should be minimal.

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The supercharger concept, in its basic form, is a compressor that increases the pressure of the air entering the combustion chambers. It consistently provides a more immediate, linear and predictable output than a turbocharger since it boosts on the intake side, rather than relying on the exhaust flow for boost, as turbochargers do. 

Supercharging is not a new concept for road-going motorcycles, in fact, it’s currently being employed by Kawasaki to make its H2 super sportbike series extra heart-poundingly fast. That design is similar to Honda’s concept only in the placement of the unit above the transmission. Kawasaki’s supercharger is centrifugal and engine-driven, offering their greatest output at high revs. Not a problem for a sportbike intended for high speeds, but a terrible idea for an ADV bike pointed at off-road excursions.

Honda’s version, depicted in the three engineering patents recently filed with the Japan Patent Office, uses a volumetric compressor that’s geared from the crankshaft so that it delivers a fixed amount of boost throughout the powerband. That means that right from idle the turbine is rotating, providing a steady, predictable boost in torque. 

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The twin-screw double injection component is a more unusual adaptation, undoubtedly gleaned from Honda’s extensive background in automobile engineering, where this technology is regularly applied as a way to decrease emissions while maintaining the best possible engine performance. 

In Cycle World’s technical breakdown of the patent drawings, it mentions it’s not the first time Honda has flirted with the idea of a direct-injected Africa Twin, as shown by separate patents filed over a year ago, but it is the first time we’ve seen a design that incorporates dual injection, a potential boon for ADV riding as it would surely improve mileage, creating a longer, more adventure-friendly range. 

However, one drawback of a supercharged engine for the Africa Twin would be its probable requirement for premium fuel, not always easy to find in the boonies. When I recently tested Kawasaki’s supercharged H2 SX SE I had a situation where I could only add mid-grade to the bike. An hour later the engine light came on and the supercharger quit —  hopefully as a turbine-saving precaution — ending my ride. 

As we all know, patents are worlds away from actual production, but with several detailed patents filed for a supercharged Africa Twin since last year, it shows this is a long-running project for Honda. In this particular case, a supercharged Africa Twin does make a lot of sense for Big Red, assuming they plan to bring their flagship ADV bike more inline with premium offerings from the top European brands.

Not that we need the top-end power of a Ducati Multistrada, on course to deliver a stunning 170-plus hp from its new for 2021 V4. But a linear bump in torque and mid-range in the Africa Twin would be oh-so-welcome, especially if it comes with little to no weight gain or extra expense. 

Author: Jamie Elvidge

Jamie has been a motorcycle journalist for more than 30 years, testing the entire range of bikes for the major print magazines and specializing in adventure-travel related stories. To date she’s written and supplied photography for articles describing what it’s like to ride in all 50 states and 43 foreign countries, receiving two Lowell Thomas Society of American Travel Writer’s Awards along the way. Her most-challenging adventure yet has been riding in the 2018 GS Trophy in Mongolia as Team AusAmerica’s embedded journalist.