Originally Posted by
grumpus
Trigger shifters, where you press one lever to shift up and another to shift down, often suffer from dried up grease that stops the mechanism from ratcheting. You can often get these working again by squirting WD40 or similar into the lever while shifting it up and down. Shifters often get frayed cables inside the mechanism, a new cable fixes it. Just replacing inner cables can make older bikes look, feel and work better - buy them cheap in bulk, but not too cheap because those can be nasty.
Yeah I know some of them are frozen I get that I tried the WD and sometimes when you don't know they're frozen you push on it and snaps but others everything moves except when you push the levers you don't do anything you can hear it working inside but the cable doesn't move