Re: why....dont bicycle shops...
Motorized bikes is a niche market. I think one of the few viable business plans for selling "custom motorized bikes" is to focus on the high end "vintage replica" market. Think of were the money is at. It is not the young guys that want to break the sound barrier while mountain biking. Those guys want the high end bikes but there are not enough of them that can afford it. Which is way most "companies" offering Moroni powered custom frames are part time wannabes working out of a garage (no offense intended). The money is in the 50+ retired/semi retired motorcycle/vintage bike enthusiast. They have the disposable income and the time to play with such a toy. If it was marketed properly and built right you would do well.
Look at the cheap chinese scooter sites. Check out the styling on all of there stuff. it is designed to appeal to a certain demographic. You won't see a lot of retro european style scooters (ie an old Vespa) because the kinda of person interested in that style scooter has the money and resources to buy the real thing. You will see an OCC wanna be chopper because half the demographic that like such things will never have the money for a real one.
Look at the custom car industry. There is a whole market surrounding the building and tricking out of these "fast furious" type japanese street racers. Not much of a market/profit in selling tricked out Honda Civics, but plenty of vendors for after market parts to do it on your own. That is what Motor Biking is for most of us. But look at the classic car market. Vintage muscle cars and classic cars have a thriving market for finished products, and look who is buying them. That is were you need to go if you want to make decent money selling motorized bikes. And it is such a niche market, that a bike shop would no longer be in the bike business if they were to successfully build and market motorized bikes.
Just my arm chair analysis of such things. I might be wrong and it won't hurt my feelings if you tell me so.
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