I know that there is two types of tire size systems. But this company that I ordered a m-12 from must be tryin to tell me there are 3. I ordered a 120/90/18, they sent me a 100/100/18. I was pretty upset, I need a new tire for this weekend. I call them up and they say it is the same size and its just "Euro" system. Come on, that is bull. Then she tells me shes gonna ask a guy there that rides alot to see if it will work. I said "I know it will work but that is not the size I ordered". She said I could send it back but they would just send me the same size again because that is what I ordered. Does Michelin size differently then every tire manufacturer on earth. I know how to read the tire size numbers.