Mine isn't actually built yet--but I wanted mine as a second means of transportation, if my car is unavailable and I need to get somewhere looking not-sweaty.
I could have bought a motorcycle, moped or scooter of course, but I can easily fit the motorized-bike into my SUV, adding to its flexibility. And the motor-bicycle has no attached costs, where either of those other three choices would have registration and insurance to pay for; I considered them but doubt I'd use even a 50-cc scooter enough to recover the monthly costs of simple ownership.
The "second vehicle" advantage is especially a matter of concern as I plan to move to a part of the US where I have no relatives nearby.
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The motor-bicycle is something unique, not as a direct substitute for anything else I have. I have regular bicycles I ride a lot now, and the point was not to stop riding them at all. I use them to get most places nearby now, need the exercise anyway and have no problems with it--but if my car was unavailable and pedaling a bicycle wasn't attractive, I'd like to have another way to get around.
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