The largest 451 tire that will fit through Shimano dual pivot brakes. A good touring tire for the 451 user who values comfort over speed. +
Bike Friday bikes can be built with either 451 and 406mm rims. Both sizes can be referred to as 20" wheels, when the 451 is a larger rim. Confirm you have a 451 or a 406 before ordering by looking on the side of your current tire to confirm the rim diameter.