Putting a 21" front wheel on the rear

[surplus223]

I was wondering if anyone has heard or seen or even thought of putting a front 21" spoke on the rear. Rim hub and all. I want a 21" wheel on the rear. But i dont want an xs650 rear hud it is too big for my taste and the look i want for my build. My thought was to take something on the lines of a yamaha DT250 21" front wheel and making and mounting a "conversion" plate to the hub that is drilled and tapped for the xs650 rear sprocket. Want some thoughts? In theory is seems possible . I would also be running a front brake. So to me I would have as much brake surface with them combined as a build using only the rear brake.

 

[XSLeo]

It might work ok, but why two threads asking the same thing?
Leo

 

[surplus223]

I thought I posted it in the wrong place.