My chain pops when i shift to a certain gear

Question

I have a trek 3700 21 speed, when i try to get it on a higher gear, the chain pops, I'm about to take it to a repair shop. Anybody know why and like how much should it cost me for the repair.

Answer 1

Most likely your limit screws are not set correctly. This is most often the case with the front deraileur. This adjustment will probably cost you $10 per deraileur. Try to go to your bike shop when its least busy. this will help in getting your bike back the same day.  

Answer 2

Most probably, the derailer (front &/or rear) needs some adjustment. This is a fairly common occurance, because the cables can stretch over time.

The meantion of the limit s***w adjustment is highly probable.

If you brought the bike from the repair shop you meantioned, and it's during  off-peak business hours, most likely they won't even charge you for the work..

It can be a 5min (or less) job for them to fix it, often on the spot, with no waiting.

Some shops consider it part of their customer service (my local shop does anyway)

Answer 3

It would either be:

1: Chain not lubricated correctly

2: Rear Derailer not set up correctly or needs adjustment

3: Cassette (Sprocket looking thing in the back) is damaged or warn. EX. the teeth on the cassette or starting to look like shark fins and rounding off on top, so the chain slips off them.

Here is a helpful web page for slipping chains. Very helpful.

http://www.athenscyclepath.com/wconnchai...