These smaller tires are actually becoming more common as the vintage VW and hot-rod guys are using them as well.The "smart-car'' also uses another size that will work for us. I use a 135R15 on my R1100GSA rig but a 145R15 will fit on the 1150 because of the different lower fork design. A search on the internet or ebay will give you some options for these tires. I see that 125R15's are even available again. I had not seen this size tire for several years, and was popular for use on some older Airhead sidecar rigs using 15" auto rims.