What's it got for gears/shifters on it? I fixed a friend's mtn type bike that had 7 speed Shimano.
It was the type that the click shifter and brake lever were built into the same assembly, and his would not shift in front either. I did take his apart (near parts explosion), but later figured out it was just solidified lube causing the problem, and probably could have fixed it with a bunch of WD40 or similar. Once I got it cleaned out, I just re-lubed it with some Superlube, and still working fine several months later).