If you need advice that particular kind of DIY, feel free to post here and tag me or DM me directly. Hopefully I can be very helpful to some of you folks who either can't afford to pay expensive mechanics or want to learn on your own.
I work as an independent mobile mechanic in middle Tennessee (for now). My primary work is motorcycles and small engines, but I've done plenty of work on cars too. I used to post quite often on r/fixxit back before I left Reddit.
Pic is an example of my work. That's one of my motorcycles, which I resurrected from the dead. I took that picture while was riding to the small town of Cave-In-Rock, Illinois, to rebuild 4 carburetors for a customer, and in line waiting on a ferry to cross the Ohio river.
Motorcycles and battery tech really don't go together well because batteries are inescapably heavy when scaled up to the power and range demands of a proper motorcycle. Most street bikes have at least 120 miles of range and that's more than the first mass-market electric cars had. Hybrid would be even worse than pure electric for weight. Hence why almost nobody's making them.
If you paid someone enough to make it, of course you could buy one. But you'd spend mansion money. A two-wheeled hybrid would have to be engineered from scratch. I can't think of a single motorcycle made and sold in the last couple decades that hasn't been designed specifically around its internal combustion engine. They're not meant for easy powertrain swaps and nowadays they're built tightly together. Balance is also incredibly important on a motorcycle and even just a few pounds in the right places can massively change how it rides.
Small motorcycles are already stupid efficient, too, so that's another reason why a hybrid isn't a common idea. The fuel-injected Honda Grom can achieve over 100MPG on regular gas and fuel-injected scooters can get even more. What would be gained in fuel efficiency would be lost to the weight of the whole hybrid setup.
Anyone can attempt a home project with enough time, money, and ingenuity though.
I could perhaps see something like a Ural sidecar rig having a hybrid drivetrain thrown into it since weight and balance isn't much of a concern. You could easily throw 200 pounds of batteries into the sidecar without causing any problems, and put a motor next to them to drive the axle from next to the outrigger wheel. Ural makes 2WD models so on those there's already a driveshaft out there. But that's a 3-wheeled contraption that already weighs plenty.
Damn, thanks for the write up!
Wish I could add something useful to it, haha.
It's a neat idea, but you know what the most practical "hybrid" on two wheels already is? A hybrid between human pedal power and an electric motor: the E-bike. Honestly if they weren't so expensive they'd completely wreck the 50cc scooter market. Very similar use cases, lighter, about the same speeds, more nimble, easier to park, and better exercise. In a place with decent bicycle infrastructure they're absolutely ideal.