Hi, I decided to try to save some money and replace a broken grip shifter myself. I have an entry level bike, Trek Navigator 200 which had Shimano C101 integrated grip shift/brakes and Shimano C101 3 gear front and 7 gear rear derailers. This is the first time I've tried to do any derailer adjusting. My lbs gave me a SRAM 7 speed grip shifter to replace the broken shifter and I got it connected to the rear derailer but I can't get into high gear and I need to sometimes click through a couple of gears to make it shift one gear. Also, now when I'm in high gear on the shifter I'm actually in low on the derailer, which I understand to be because the C101 derailer is backwards from most derailers (not a problem, but I thought I should mention it).

I read Sheldon Brown's site and he said normally limit stops shouldn't be necessary after a cable replacement but indexing will. So I haven't made any adjustments yet to the stop limits and am not sure about indexing adjustment. Is this the B-tension adjustment? I see two bolts which I believe are the high and low limit stops but I don't see any B tension adjuster. Any one familiar with this derailer and ideas on how to properly adjust the derailer?