Kawasaki are teasing a hybrid.
That has me intrigued.
After building my own electric I've toyed with the idea of building a hybrid.
A bike with an engine which is not powerful enough to provide great performance on it's own, running a generator. But the fact that it can keep the generator running at full output means it assists the battery power when needed, and charges it on the overrun. That would make it a 'series hybrid'
The downside is, if you don't make it a removable 'range extending' unit, then you're effectively carrying two engines, a generator and a main traction motor all the time, when only the traction motor is providing the drive at times, so a lot of weight and space for no return.
A part time petrol assist, or the other way around, where the electric motor provides the assist,(means you only carry a traction assist motor and an engine), makes it a 'parallel hybrid'
Honda got there first I think with the mk1 Honda Insight (alluminium honeycomb body, nearly impossible to repair). They turned the engine's flywheel into the magnetic rotor component both for the generator and for the assist motor..
Something like this last system might work on a bike, because you already have an engine and a flywheel/rotor permanently connected. There's a couple of videos on Youtube of people playing about with something like that. Obviously though, because the flywheel is always connected to the crank it means that when you are motoring on electric you also have to turn the engine over, hence why it could only be used for assist/boost. Decoupling the flywheel from the crank would give the best of both worlds but that means a complete redesign of the drive to the gearbox. Alternatively, fitting one of your wheels with a central hub motor could do well enough to carry you around town in silence. In Edinburgh all the city centre roads are 20mph limited now, so that would be ideal, in terms of efficiency and noise
but in theory, a 125cc engine, with an oversized rotor charging a traction battery, with a 'bidirectional' charge/drive controller, might be able to give another 3HP boost. 3HP of electric power is much more useful than 3HP of internal combustion at lower speeds, due to the instant torque of an electric motor. Scaling it up to larger engines is probably going to work too, up to a point.
The usefulness of that is that you could recharge the batteries at home too before setting off, so if your commute is a short distance you might never need to pay for petrol except on longer runs. 2p per mile for electric, versus 7p per mile on petrol. But I mean, if you were so hard up in the first place you probably wouldn't be able to afford to buy that sort of bike in the first place ! Conscientious greenies might be keen though
I think the manufacturers know that they could create a selling point for their new bikes by making them hybrid, but then what will that mean in terms of legislation - will it make legislators think that they should bring forward the introduction of an 'electric only' policy ?
Edit. I just noticed this on fleabay. It's the rear wheel of an electric motorcycle, claimed speed of 65mph. That would make a useful front wheel conversion. Maybe not on the TDM because it's already a bit heavy, but my KTM is needing some work, it's already light and has space for some batteries. Tempting, apart from the fact that it adds a lot of usnprung weight going from an alloy rim, to a rim full of heavy magnets and iron. It might get a bit thumpy on potholes ! https://www.ebay.co....H8AAOSwXIpgOCxf
It could be exciting having it boost the power, but the KTM already lifts the front wheel easily under power so I'ld just be spinning it in the air for nothing ! And it might be a big fight to get it turned into corners too....
Edited by fixitsan, 02 March 2021 - 09:12 am.