I am not sure this is the correct post, because I am talking preventative maintenance. I have Deore shifters and derailleurs. I was constantly having to tweak the index on the rear derailleur and run oil down the lines.

A neighbour had given me an SIS Shimano cable kit when cleaning house, and finally, jacked off with the whole deal I decided to replace the cabling to the derailleur. These are the ones where there is sealed oil/grease in the cable covers. Well, it is the best maintenance reducing, ride improving step I have taken. I have no idea what they cost but it must be peanuts, so I recommend it to all commuters.

I get a smooth shift: water, dirt and time don’t stiffen up the shift.