Originally Posted by
Khoorxr
I tried changing out the 36t chainring on 6800 ultegra 46/36 chainset to 34T, the shifting performance becomes quite bad, the chain pickup don't work properly. Are you guys facing the same issue when you change from 36t to 34t ?
Unfortunately IMO modern front derailleurs are built with ramps that are meant to work with specific chainring tooth differences. By going from a 36 to a 34, the ramp now sits above the chain when it’s on the 34. To fix it, you have some choices. You can get a smaller big ring (44 teeth) and lower the derailleur on the seat tube, which should put the ramp in the right place again. Or, you can find another derailleur designed for a 34/46 chainset. Or, you can get an older front derailleur that has no ramps.