Originally Posted by HillRider
If the rear derailleur is NOT a Dura Ace, it will work fine with the 10-speed shifters.
I believe there is a cable re-routing technique that will even let you use pre-9-speed Dura Ace derailleurs but any non Dura Ace derailleur will work with no alterations.
DA10 barcons are compatible with other Shimano 8sp deraillers, but not with DA8 deraillers?! That's really weird. You'd think that DA10 shifters, if they are compatible with all other Shimano 8sp stuff,,, well - you'd think it'd be compatible with DA8 deraillers too. Why is this?