My Haibike runs everything internally. I wasn't in the mood to pull the shifter cable to lube it. Turned the bike upside down in the stand, and started dribbling some thin chain lube I had on the bare cable back by the derailleur. Just a few drops so it ran down the cable into the sheath. Did that every 20 minutes or so, for around 4 hours. Left it upside down all night. In the morning, the effort was at least half what it was.