Technically the frame's got to be 25 years or older to legally import a bike to the US and get it registered. I.E. DOT/EPA exempt.

Most.....99% +- of all the 1960's/70's claimed era bikes that have entered the US are imported with "aged" documentation.

You can do it legally but it takes more time and expense to track down a genuine vintage frame, there are subtle differences...............and as Butch suggests if you are not careful you end up with gen-u-whine.

Anything in China can be faked.........buyer beware.

Thing is...........I've nothing against the practice of "aging" the paperwork if the dealer is up front about it and you are not being sold a newer bike that is being passed of as vintage for the dealer to make more money or negate some IMHO...... stupid import regs..........as long as you know about it.

I say stupid regs because...........as far as DOT and EPA goes there is no difference in the technical characteristics as far as DOT and EPA are concerned from a bike built in the 60's-70's-80-90's till now........same crappy brakes, tyres and same old technically backward motor..........they both pollute the same.

You'd be no safer..... neither would the environment if you rode a 1930's era BMW R71 or a 2000 CJ M1m.