Originally Posted by
Lemond1985
All Shimano rear derailleurs that are 6, 7, 8, 9, or 10 speed have the same amount of pull, and so are interchangeable. So there is no such thing as, for example, a "7 speed Shimano rear derailleur" all of them pull the same amount of cable per shift....
Isn't Tiagra 4700 the exception to that rule? It's 10 speed but doesn't use the previously standard pull.