Swapping wheel compatibility depends on a lot of things. Fronts are more straightforward with only axle size, brake tab location/type, and wheel size to consider. also speedo drive if you're intending to keep that... Rear's much trickier though and the things that'll get you are: 0) before anything - drive type - you can't put a variated wheel like hobbit or vespa, onto a chain driven bike. duh. 1) sprocket availability - some wheels don't have sprockets that match the gearing you need for your engine. Also chain size can vary, but 420 can fit on a 415 sprocket. 2) drive side. puch rears have the brake and sprocket together on the left side, and a pedal freewheel sprocket on the right. many other bikes only have one sprocket and the brake on the opposite side. This may mean you lose pedal ability or have to rethink brake tabs 3) brake tab. the brake plates slide around a nub or tab to hold them in place. If the brake is on the other side of the wheel or the size/shape/location of the tab is very different you'd have to make or modify a tab to hold the brake plate. 4) axle size - typically axle diameters are same, length is usually OK too, might need to space it a bit with washers but this is rarely the deal breaker. 5) wheel size obviously matters, 16 or 17". you can put 16's on a 17" frame, doesn't affect much but aesthetics and gearing a bit. 17's on a 16" frame may be a tight fit or may not fit at all, depending on bike and tire selection.