It will come as little surprise to those with a keen eye on the motorcycle industry that major manufacturers’ ideas to electrify their lineups are starting to look more like long-term aspirations than solid plans as slow customer take-up and a lack of game-changing revolutions in battery or motor technology means product planners and R&D departments are dusting off ideas for future internal combustion engine developments and searching for cost-effective means to cut emissions without sacrificing performance or alienating buyers.
Where ICE development had been shifted onto the backburner, with multiple governments putting forward ideas for bans on non-zero emissions motorcycles earlier this decade in the expectation that electric bikes would proliferate, there’s been a reversal in that thinking over recent months. Electric bike sales have remained in the doldrums – dropping over the last couple of years across Europe rather than increasing – so it’s understandable that manufacturers will be rethinking the distribution of the R&D funds, with more being funnelled towards combustion engines as that technology looks like it’s going to remain relevant rather longer than they previously posited.
On four wheels, car makers that had previously sworn to go all-electric are performing U-turns faster than most of their vehicles could manage. Mercedes, Volvo, Audi, Porsche, Bentley, Alfa Romeo, Ford, Lotus… All have backtracked on their previous EV plans. Motorcycle companies face an even tougher task to persuade customers to switch to EVs and a greater challenge to make the technology into a viable replacement for existing combustion engines, and it’s increasingly clear that the result is a renewed focus on finding a route forward for ICE that meets environmental requirements without decimating sales.
One such technology, previously shunned in the two-wheeled world, is forced induction. Turbocharging has become ubiquitous in modern combustion-engine cars, allowing smaller capacities and improved emission and economy without sacrificing performance. Just look at the Mercedes AMG 63 models: starting out as 6.2-litre V8s, they dropped to a twin turbocharged, 4-litre V8 and then a 2-litre turbo four-cylinder with a hybrid system – each time getting more performance as the engine got smaller. On motorcycles turbochargers are still eyed with suspicion thanks to the brief spate of boosted bikes in the mid-1980s, when everything from watches to vacuum cleaners were emblazoned with TURBO logos. Those models – the Honda CX500 Turbo, Yamaha XJ650 Turbo, Suzuki XN85 and Kawasaki GPZ750 Turbo – earned reputations for poor throttle response, turbo lag and performance that would soon be outgunned by lighter, higher-revving normally-aspirated engines.
Today’s technology means that the downsides of turbocharging – most importantly the lag between twisting the throttle and the turbo spooling up to provide meaningful levels of boost – are a thing of the past, opening a pathway towards a new generation of lag-free, small-capacity, forced-induction engines that could make for smaller, lighter and more efficient motorcycles, hitting environmental targets and simultaneously adding an intriguing technology that’s likely to attract customers in a way that electric powertrains currently can’t.
Never has the evidence of this been clearer than with the debut of Honda’s V3 concept bike – simply an engine in an unclad chassis – at last year’s EICMA show. It grabbed the sort of attention that electric bikes could only dream of, promising an eco-friendly future for internal combustion thanks to its adoption of an electric supercharger. Unlike an exhaust-driven turbo, the Honda e-blower can be spun fast enough by its built-in motor to build up boost before it’s needed, and as such should ensure immediate throttle response from the unusual V3 engine. We still don’t know the engine’s capacity or its power output, but the addition of boost means it’s sure to be smaller-capacity than similarly-performing normally-aspirated designs, offering advantages in economy and emissions.
Yamaha has been delving deep into the potential of forced induction as well. Back in 2020 it presented results from research on an 847cc three-cylinder prototype that featured direct injection, variable valve timing and an exhaust-driven turbo, packed into the chassis of an MT-10 that would normally use a 1000cc four-cylinder. The results included a 30% reduction in CO2 emissions compared to similarly powerful normally-aspirated engines, and a torque curve that gave a flat plateau peak all the way from 3000rpm to 7000rpm while beating the maximum that even Yamaha’s 1700cc V4 V-Max could achieve. Peak power – around 180hp – came at a mere 8000rpm, around 4000rpm lower than a litre four-cylinder making the same maximum. More recently, Yamaha has filed patents showing a similar turbocharged three-cylinder engine but including an electrically-assisted turbo, still using exhaust pressure most of the time but with a small electric motor to spin up the compressor before the throttle is opened, eliminating turbo lag.
Suzuki, too, has developed its own modern turbo bike engine, a twin derived from the existing GSX-8 design, which can trace its roots back to 2013’s 588cc turbocharged Recursion concept bike and the XE7 turbo engine that was shown in 2015. The same company also filed patents for a four-cylinder turbo bike using an electrically-assisted turbo long before Yamaha’s version emerged, as well as a turbocharged V-twin cruiser model. Kawasaki, of course, is the only one of Japan’s ‘big four’ that already offers blown bikes in the form of its four-cylinder, supercharged H2 models. Forced induction, in short, is on its way to mass-made motorcycles.
And with that comes an opportunity for White Motorcycle Concepts. Future turbocharged or supercharged motorcycles will, in the pursuit of reduced emissions, have smaller-capacity and physically smaller engines than similarly-powerful current designs. That opens the door for WMC’s patented aerodynamic duct technology, since a small, boosted engine could allow more space for the internal duct that reduces frontal area and drag, amplifying performance gains or allowing for an even smaller, more efficient engine to be used without losing out.