mtb Wont shift to third gear

Dingoni

Hey everyone I have been having this problem where the gear seemed like they are getting jammed up like after lets say like 200 ft of peddling the gears will stop then kind of fly forward then go back into pedaling then it will repeat this problem. Now i noticed that when im in 2nd gear it wont shift to the third gear the chain will sound/look like its about to lock on but wont move.
This has been making me very sad lately, I have some serious knee problems and mountain biking and riding seemed like they are the only relief and to help to build strength back from the pain. I havnt been able to ride everyday and my knees are killing me and my moods are going down with out my favorite activity of riding the trails. I called the bike shops and they wont be able to get it back to me until thurs im currently out of town and leave weds. If you guys could help me that would mean the world.

thanks,
Dingo

Dingoni

i have a specialized xc 2010 full suspension

supersonic

Have you tried adjusting the gears? Mech hanger straight, and gearcables clean and oiled? How old are the parts, could they be worn?

Dingoni

How do u adjust the gears and the Mech hanger straight? parts are relatively new i guess. I ride hard but my new to the tech work of bikes. i can figure things out pretty well but i dont want to just start disassembling

thanks so much

cooldad

Google the Parktools website and find the bit on indexing gears.
Bikes need routine maintenance - you'll also find plenty of info there.

Dingoni

thanks!

The Rookie

when your talking of 1,2,3 is this at the front or the rear, at the rear you start in 9th (smallest gear) with no cable input and head to 1st (biggest gear closest to spokes) as you pull the shift cable with the lever.

Simon