It's the one with the carburetor.
And this is the bar thing welded onto the frame that the exhaust pipe hits when it is in position. What is it?
More pictures of the bar with the exhaust pipe removed.
What is it? Can I remove it?
It is the Leo Vince Hand Made Model 4075. On the box it says it is for the following bikes:
Aprilia SR 50 Sport Pro ie (Motore Piaggio)
Aprilia SR 50 R Factory (Motore Piaggio a Carburatore)
Piaggio NRG 50 Power DD
Gilera Runner SP 50 (Mod. carburatore)
My Italian is not too good but the second one of those looks like mine as I do have a carburetor.
OK job done. We removed that welded on bar on the bottom of the frame. Here's how:
Get the trusty Dremmel out.
Now it fits lovely.