t realy depends if yer got casset rear hub or flip flop hub or just a std one with casset hub yer can go as small as 9t rear cog with 25t front if yer got flip flop hub (got thred each end of hub but one little smaller) yer can get a 12/13t freewheel then yer goin to be lookin at 32/26 front cog , if its a std hub lowest yer can go is 16t freewheel
