Bike Friday use two different size tyres on their bikes and although they are both classed as 20" they are different diameters and are not transferable.
The smaller 406 size is used by many other manufacturers, and is actually the same size as BMX bikes so there are many options available. The 451 tyre is slightly larger in diameter and is generally narrower and capable of holding a higher pressure making them the preferred option for the performance folding road bikes.
Below we have separated the popular Bike Friday models into their respective tyre sizes, but if you are still unsure about which tyre would best suit your purpose please don't hesitate to contact us and one of our team will be happy to guide you through the options.