Dia Compe ENE Down Tube Shifters
The Dia-Compe ENE shifters are copies of the Suntour Micro ratcheting shifters and one of the best shifters of all time (only the discontinued Simplex retro-friction are slightly nicer). Still, these are so smooth and the ratchet equalizes upshift and downshift effort so perfectly that they will satisfy even the most demanding randonneur. These shifters are made by Dia-Compe so the quality is first rate.
They work with 5-speed to 9-speed cassettes and freewheels and most common dérailleurs. (Note: most SRAM derailleurs don’t work with non-SRAM shifters.)