I'm new here and was hoping someone could help me out. I have an older (94) GT mountain bike that's having shifting problems. Basically I was riding it and the chain went into the smallest rear ring and pressing the shifter does nothing.
I replaced the cable thinking it may just be worn and this did nothing. If I mess with the small adjustment screws on the rear derailler the bike will shift to the larger rear rings and then shift down to the smaller rear rings but not up again. Which leaves me back in the smallest rear cog. I'm a real novice at working on bikes so any help is appreciated.