New bike chain problem

[akspecialist]

I got a new 24 speed specialized a few months ago and I'm having problems with my chain.

On certain gears the chain jerks. I took it in for a free 30 day tune up. Before that it was the 4th gear and now the 7th gear is starting to act up. The gears also jerk when I put pressure on them.

The pedals were also doing something weird. I'm not technical, I'm trying to learn, but I would describe it as something loose. There was a pulse that eventually turned into a wobbling every rotation. The shop I took it to did a pedal realignment and it worked fine for a while.

Like I said the bike is new so its not that something is worn out and needs to be replaced (or at least it shouldn't be). If you could also think of what I might be doing that would lead to this that would be helpful. I'd rather not unintentionally ruin my new bike.

Thanks

[nfmisso]

Take it to the shop you purchased it from.

Have the derailleur cables been adjusted?

[cny-man]

Ask for the head mechanic to go over the bike, as previous trips did not resolve the problems. There's no such thing as a "pedal realignment" so if someone used that term at the shop I would make sure that person does not work on your bike.