Disclaimer: I'm clueless and am piecing together what little information I know from reading this site and from watching YouTube 'intro to repair' videos.
I've been gifted a used mountain bike, my first since I was a kid. It had a few issues, though. I managed to fix the brakes, but the shifter is giving me problems.
The bike in description is a Giant Boulder SE from the 1990s. It's got 3 speeds on the front and 7 on the rear, and operates using thumb switches.
I can't switch gears on the front at all. By loosening the shifter cable a little, I gained the ability to click through the gears, but the derailleur/chain never makes any changes. It's always stuck on the outermost ring of the front... set of rings. (Cassette, I think.)
I think the larger ring represents a higher gear, but clicking through to top gear and then lowering it back down to 1 does nothing.
At top gear, the shifter cable tension is such that I can get a finger between it and the frame, and wobble it about 5mm, but it's still taught. On first and second gear, the cable is much looser.
This is a problem because riding in first gear kind of sucks, and by kind of, I mean really.
I have tried adjusting the limit screws. At first, I saw some movement, but now tightening or loosening either screw seems to do nothing at all.
The rear shifter starts at 7th/top gear and 'releases' downward, towards gears with less resistance. I can go between 5th, 6th, and 7th gears, but trying to go any lower than 5 won't work, as there's just too much resistance from the shifter.
I don't think this is a huge deal, because 1st-in-front-5th-in-rear is a plenty low enough gear to get started/climb the kind of hills I'll be climbing anytime soon. But I thought I'd mention it anyway. My instinct is that this means the cable is too taut, but my instincts are garbage because as I said, I'm clueless.
Any help here would be really appreciated. Can't really afford to take it into a shop or that's what I'd do.