Shimano in fact intended the 5600 105 triple front shifter for double duty as well. The customary way to implement this is to lock out the third ring on the outside using the high limit screw, letting you shift between 1 an 2. Care must be taken to ensure there's enough tension in the cable that you're never tempted to pull past the second ring position. The problem is if the cable loosens and the upshift doesn't happen, the rider instinctively shifts again. This jams the shifter in the third position with cable up tight against the limit screw. The subsequent downshift against the tight cable either breaks the ratcheting mechanism right there, or if you do it often enough, it will break soon enough. This was occurring so frequently, often on bikes set up by shop mechanics, that Shimano hastily released a double front shifter for 5600. [color=c0c0c0]But, if you use care it will work. If you've found yourself shifted into the ghost third ring, just remember to dump the excess cable tension, by releasing the cable fastening bolt or loosening the high limit screw on the front derailleur, before downshifting. The happy news is that once your shift housing is seated cables don't stretch a whole lot until they're ready to break. The alternative that I've heard about is to lock out the non-existent inner ring so you're shifting between 2 and 3. The problem with this is that if you accidentally shift to one, you have a very slack cable that can get dislodged. Your triple front derailleur might work fine for double rings. So might your crank after you remove the inner ring. Chain line will need to be resolved. If you have Hollowtech II cranks, move the plastic shim on the drive side to the non-drive side. If your cranks use a cartridge bottom bracket, you will need a new one with a shorter spindle. Of course, if you replace all this it will go together seamlessly.[/color]