single word requests - What is the name of a repair shop specialized in fixing flat tires?

There is no single English name for a repair shop specializing in fixing flat tires, as Bill points out.
Names for business types, like names for food. are intensely cultural and vary widely from locality to locality, and thus from language to language.

In English one only finds names for businesses that are commonly encountered in Anglophone areas. This is just as local as anywhere else. In Mexico, for instance, to refinish a desk, one buys varnish at a tlapateria but new drawer pulls at a ferreteria; in the U.S. one buys both at a hardware store.

There are stores in Mexico that just don't exist in the U.S, like a refaccionaria, where one buys spare parts (refacciones -- in Mexico; in Guatemala refacciones means 'snacks'). They stock spare parts for just about anything, from cars to kitchen blenders. There's nothing like that in the U.S.