The rim for the Vespa Cosa (2.50-10) has 0,4 inch more width than the Vespa Largeframe and Smallframe rims with the usual 2.10-10 dimension.
So the rim can be used as a moderate conversion rim. A low profile tire in the dimensions 100/90-10 can be used. Depending on the manufacturer of the tyre, however, attention must be paid to the tyre clearance at the fork and clutch cover. There are considerable differences in width from manufacturer to manufacturer, despite the same size specification.
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