this is my 1st bike, it's an 08' tricross sport and i just got the thing a week ago, i rode it in the rain today and when i got home, i took the back wheel off to get it clean and just to see how it comes off, it was my first time doing that, well after i put everything back together i tested the gears and brakes and everything seemed fine. the rain let up and i took it to home depot to get a tool i needed, on the way there it kept jumping gears on it's own. i got it back home and tried taking the wheel off and adjusting it. now it seems to not go into the gear that i have selected from the shifter. ie: when i'm in 1st and shift to 2nd it just stays in 1st but when i shift to 3rd it will go to 2nd? and i have the same problem on the high end as well in 9th i shift to 8th and nothing then when i go to 7th it will jump into 8th?
can anyone help me or do i need to take it to the bike store?
you might check the chain for a bad link. I had this happen to my tricross (also a 10-speed) after a ride. It was totally fine on a long ride on sunday. Parked it for the night and rode it to work the next morning. From the get go it was jumping gears every pedal revolution. After i got to work i tried to adjust the RD to no avail. I rode home gently with the same problem.
Once home i got it in the stand and found a (very) stuck link in the chain. I fixed that and all was well again. It was driving me mad on my commute though. It's pretty easy to find if that's the problem, just back-pedal the crank slowly and watch the chain come through the RD - that'll show you any stuck links..
If that's not the problem the RD is probably a little out of whack. Read this and you'll most likely be all set: