Hybrids are probably the best way for most car drivers to get electrified right now. Radically lower fuel costs, clean full-electric driving for the majority of daily use, total freedom to take long highway trips, fast fill-ups at abundant gas stations ... They offer a best-of-both-worlds proposition.
But cars are big enough to carry the added weight and complexity of an extra powertrain. Motorcycles are not, and adding weight has such a huge effect on their handling and performance that most of us dismissed the idea of a hybrid step in between the gas and electric worlds as soon as we thought about it.
Kawasaki, it seems, did not. In a video released last week, the Japanese manufacturer has shown its vision for hybrid motorcycles, along with a working prototype on a dyno, and laid out how it expects things to work.
It's logical enough; the electric powertrain will do all the work in the stop-start environment of the city, where electrics excel and can recapture a lot of their expended energy. On the highway, where the unrelenting task of pushing through wind resistance puts a nasty drain on a battery, the combustion motor takes over and does its thing. And in the twisties, where there's lots of hard acceleration and braking as you slow down for corners and power out, as well as a range of speeds, the two motors will work together in synergy.
From looking at the prototype, it seems Kawasaki will be running a single-speed system that will manage the contributions of the two motors automatically. From a standstill up to a certain undefined speed, it's all electric. The combustion motor starts up at a certain point and puts itself into the mix with what looks like a bit of a jolt – but then again, this is a dyno run, so it might well have been done at full throttle.
If it is indeed a single-speed system, the combustion engine is likely geared as if it's stuck in sixth. At slower speeds where the engine might struggle to give you much acceleration, the electric motor is there to help. Acceleration shouldn't be a problem; we've generally been very impressed with the shunt you can get out of electric motors. We suspect the engine can also run as a range-extending generator for slow speed work when the battery's depleted.
This sounds like a relatively small engine to us; maybe a parallel twin from something like the Ninja 300. The electric motor is tucked into the chassis behind the engine, and it seems to be a decent size. It's hard to tell where the battery pack's been sequestered – those can get big and heavy, so it'll be interesting to learn what the plan is there and how it affects the bike's overall performance.
The other key issue, of course, is cooling. This bike will need to draw heat away from the engine, the electric motor and the battery pack, a task that could get complicated depending on the packaging.
It's hard to tell whether we should treat this as a research project or a production bike in development, but the prototype looks pretty tidy, and if Kawasaki can find a battery size that strikes the right balance of range, power, weight and bulk, then package it in a way that evacuates heat effectively, and make it look cool, and keep the total bike weight to a reasonable figure, and build it cheaply enough to make the price attractive, then maybe we can get a feel for what a hybrid motorcycle might bring to the table.
That's a pretty big ask, so we wont be holding our breath, but we do like the idea of a bike that can commute clean through the week, but still stretch its legs on a weekend tour. And there could be other benefits as well; I'm thinking of a hybrid adventure machine that can preserve the peace and quiet of the off-road trails, and that never has to suck air during a river crossing. Then again, weight and complexity become even more of an issue when you step into the dirtbike world.
Still, a fascinating idea to ponder and it's great to see Kawasaki putting some proper R&D resources behind ideas like this. Check out a video below.
Source: Kawasaki
