Originally Posted by
miamijim
Dura Ace STI levers may not work with any derailleur other than a Dura Ace. Dura Ace uses a different throw ratio than Ultegra which may pose a problem. My advice is to try it. If it doesnt work the proper solution is only a Dura Ace derailleur away!!
Chances are very good the STI levers will work with your crankset.
I just changed out my worn-out & rattling Ultegra 9 speed levers with a new 9 speed DA set & have no compatibility problems at all with the Ultegra deraillers.
I have the tri-color 600 deraillers on another bike & have run up to a 12-30 8-speed cassette with 53-39 chainrings without any trouble. Just set your chain length carefully.