I'm working on a bike that needed new shifters and I've discovered an issue. The rear derailleur is a Sugino VIC high-normal 6sp on a 90's Murray MTB. It shifts fine from high to low but traveling opposite is where the problem is. When I begin up-shifting the RD sticks and does not shift above gear 2. I found the instructions for it online but with no luck. Lubing the pivot points has not helped. I suppose the worst thing would be replacing it.
Are the cables (and housing) ok?'Sounds like there's something wrong there (and the spring of the dérailleur might be worn, too, though try the cables first).
The cables are new with the shifters (Sram grip shifters). It's the original housing which is a larger diameter than the new cable and I lubed those also. The derailleur spring would seem to most likely be the problem. Though there could be a burr somewhere keeping it from moving to those higher gears like normal. If I don't go to the lowest gears (1 and 2) the movement is perfect between those gears.
I got it to work better today. Not sure how long it's been sitting or it's age but a few other components were sticky.