Note that Schwinn used a non-standard stem size on some of their bikes from that time period. Stems were 21.1mm (.83 inches) and there's not a wide variety available now. I am not sure the LeTour you reference uses this size stem, but if you wish to change stems you should inquire about it. You can, however, find several stems of 21.1 size on ebay. One nice option is to buy a stem adapter for threadless stems. I saw 3 or 4 stem adapters of size 21.1 on ebay.