48/15 is a pretty high gear for city riding. 48/16 or 48/17 might be better but your chain might not be long enough to take a 17 tooth freewheel. 16 tooth should be fine.
@Butters started
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48/15 is a pretty high gear for city riding. 48/16 or 48/17 might be better but your chain might not be long enough to take a 17 tooth freewheel. 16 tooth should be fine.