i have a triple and when I climb I shift to the smallest gear. The chain would skip only when I shift to the innermost cog in the rear. can someone tell me why and what can I do to fix the problem myself?
i am using smallest gear in the front and biggest in the rear.
Try adjusting the cable with a counter-clockwise 1/2 turn on the barrel adjustor found at the rear derailleur.
Or if the drivetrain is old that cog may be worn out.
Also refer to the derailleur and cable adjustment instructions found at http://www.parktool.com.
Lube your cables, shifters and derailers.
Then make sure the RDR is not hitting the limit screw.
Then increase the tension on the RDR cable 1/4 turn at a time.
This guy doesn't know a whole lot about bikes. What I would do (since you don't have a hanger alignment tool I am assuming) is grab the der. and rip it as hard as you can towards the top of the rim and add a little tension to the cable.
BTW for this poster when a bike is a failing to shift in only two gears it suggests an allignment problem. Further since he is having a problem shifting from 1 and 2 it also suggests a problem with the D-screw.
Its really the blind leading the blind on these forums.
For the worn out cog guy. This is not the problem, try again.
So how do you know that the innermost cog is not worn out? I agree that's probably not the problem but I don't have any idea how old that cog is or how much wear it's had. So tell us wise one, how do you know?