As a newbie rejoining the ranks of bicyclists after many years I am taking baby steps. I am very puzzled though over one think. I bought a used Hercules 3 speed bike. I decided to buy new tire and tubes and I looked at the size of the tires that were already on the bike. The size noted was 26 1 3/8. I order the new tires in that size and when I tried to place them they looked way too big. what could have possibly gone wrong??