by Calnago on Sun Feb 11, 2018 3:14 am
Sure... the front derailleur, when properly adjusted will have the inner plate extremely close to the chain when it's on the big ring, like less than 0.5mm, when it is completely crossed big/big. And when properly adjusted, you can nail every single cog smallest to biggest cleanly with no derailleur rub. It has no trim when on the big ring. in fact when on the big ring, you just leave it where it is until you want to shift back down to the small ring. When I asked some questions of the OP, he responded that Yes, it did only take one click of the left button and the chain would drop to the small ring. That immediately tells me there's not enough tension on the cable and the derailleur is not far enough outboard. And also, that there is quite a gap between the chain and the inner fork of the derailleur when on the big ring. If it's adjusted correctly, the inner derailleur fork will actually function as a chain drop device for the Big Ring when you think about it, as the inner fork is set very close to big ring. When shifting to the small ring, it should take two clicks and you should just click right through the first click to the stop (and second clikck). If you were only to press the thumb button only once when the chain is on the big ring, the chain should still be on the big ring, but it would be in no mans land and making all kinds of noise as it thinks about where it wants to settle, big or small. Is it clearer now?
To complete the scenario of shifting to the small ring for completeness, once the chain drops to the small ring, the derailleur is still not at it's furthest most inward position, at least it shouldn't be if adjusted correctly. You have one more click left, and you'll know where that is when you work your way up the cassette to the larger cogs and start to hear a bit of rub on the inner plate of the front derailleur when you're somewhere around the 4th cog from the top. At that point it's time to push the left button once more, assuming you're still wanting to go to larger cogs, and you will be noise free right to the largest cog.