Originally Posted by maddog34

use light silicone grease on the inside of the twist shift tube...
verify that the plastic rings are still in between the hand grip and the twist shift...
maintain a 1-2mm clearance between the grip and twist shift tube....
replace the cable, replace the housings.

above is a list of things that will make the twist shifter easier to twist.

and instead of just adding grease to the hub, it DOES NEED flushed and re-greased every so often.

or wait a while longer than you have and buy a new one when the gears ruin themselves.