Originally Posted by
Al1943
Actually it's just the opposite. Shimano 10-speed Ultegra and 105 are now double or triple specific. The 105 10-speed shifters started out double/triple compatible but there has been problems with using the earlier shifters with a double crankset and more recently 105 has become double or triple specific.
The 9-speed Ultegra and 105 shifters went both ways. Dura-Ace is now double only.
Ah thank you for clearing that up. I have 9 speed 105 so that explains my experience.