I was all excited about the Piaggio hybrid MP3 until the specs came out. Seems like the same lesson learned by the 4-wheel hybrid rush of a few years ago: If the gas milage and performance aren't significantly BETTER than the gas only counterpart, people won't buy 'em. Wonder who will be the first to apply the new plug in model to the hybrid motorcycle -- namely -- high performance electric motor with a range extending gas engine.
Unhitching the ICE engine from the drivetrain allows for it to be optimized for recharging batteries. Meanwhile, the lightweight, high performance electric motor can drive the wheels. Keep the overall weight down (by using the ICE range extender instead of batteries) and you could have a fun, economic commuter that doesn't use ANY gas for most in-city trips.
The big challenge is that there are plenty of scooters that already get over 100 mpg on gas alone. My mom's old Honda SuperCub (Passport) could do it 30 years ago. So two-wheelers have a much higher road to climb to make the switch to hybrid power economical. The other problem is that -- like cars -- the increasing range and performance electric only power is making hybrids unnecessary. With production electric motorcycles exceeding 100 miles on a charge, it is a wonder that Piaggio doesn't just come out with an electric-only MP3. If the specs were right, I'd buy one.
Links: Hell for Leather: Hybrid Mp3 Grows Up | Piaggio USA