20” Studded Tire
 

https://cimg3.ibsrv.net/gimg/bikefor...78aa29b412.png
20 inch studded tire



Saw this today on Amazon. First time I’ve seen it, and I’ve been looking for quite some time.

This should fit the front wheel of a Bakfiets or Bullitt type bike, I presume.

Am I wrong? Has this tire been available all along?

Yes, it has been available and here you have a post from a decade ago. Indeed, the availability of smaller diameter tires was a problem in the remote past, but 20" were the first to appear in the market, and 24" maybe the latest.