@blip If you really want to go down that road then my first suggestion would be Japanese big 4 (Honda. Yamaha, Suzuki or Kawasake) Primarily because of reliability and parts availablity. A lot of them may well be made in China or Malasia etc, but because they have their name on them they carry support and parts for them. And when you consider prices, for a new Suzuki you are looking at $3k ish. Not really sure about the 2nd hand market but in these price brackets, the premium for a Japanese scooter can be measured in hundreds of dollars rather than thousands so not much of a step up.
If you decide it is something you want, and you are aware of traffic issues etc, then while it is not something I would suggest, I would not stop anyone either. They are cheaper to run and register than anything over 50cc which is their appeal (rego on a 50cc is $168 per year vs a bike up to 600cc at $400 and a car is $107...) . For reliability 4 stroke are better but I dont know if there are any in the 50cc bracket....2 strokes are simpler and maintenance is simpler but a bit more frequent.
I would look at what you are trying to do- will a cheap small car do a similar job because in most cases, apart from fuel usage, they will be a better option. (cheaper rego, cheaper insurance, cheaper purchase price and drier in the rain....) One final point, even though I dont own any bikes under 1000cc, I have to admit that every time I have riden a scooter, I have arrived at my destination with a huge smile. There is something about riding a bike flat out as hard as you can and not being able to get a ticket for speeding.....
Stay safe whatever you decide to do....
Bookmarks