The tires are 28×1 1/2 from classic-cycle.de...... they do not have the ISO listed on these particular tires. The prices are reasonable and they have have many abstract sizes......buy a bunch till you get some to fit. Put a little heat at them, they'll go on.Fantastic! Curious about Piercer's question too. I was thinking those might be ISO 642 tires, if so I want to order a set.