Cant down shift

[Aj935]

Okay, so about a month ago I bought this used bike to have a cheap way into the sport. It's been working great for the past few weeks, but then I started to notice my rear shifter getting tight. I have twist grip shifters. It's gotten to the point where it won't down shift at all. I'm certain it's the shifter though and not the derailleur as I can I push the derailleur into gear and it allows me to downshift if I'm holding it in. It seems like the cable is too tight or something. I'm not sure how to go about fixing this issue.

[RBurrelli]

It may be the cable and not the shifter. Will it shift I'd you manually pull on the cable? If not, then it could be the cable. Also test the grip shift by removing the cable from it to see if it operates properly.

[Aj935]

I pulled on the cable and it seems to shift that way, I can't figure out how to get my grip shift apart. I have the grips off but can't seem to get the shifter to separate.

[1FJEF]

So if you shift to the smallest rear cog, you can push the derailleur all the way across and make the chain go to the biggest rear cog? How many front chain rings do you have?

Try here. They are incredibly cheap, so you may want to consider replacing if the repair does not go well. Show/tell us EXACTLY what shifter and bike you have, # of gears front & rear.