Help with shifter, cable and, cog?

[das028]

Yesterday while out on the trail I noticed a cannot shift to the smallest cog on my bike. It looks like the cable from my shifter has to much slack in it. i believe I can fix it by just un-screwing the bolt and tightening up the slack, but was wondering if this sort of thing is common? Is it a bike matienance type of thing, or is there a bigger problem? Should i take it in the shop or is this something I can handle at home? Hope this makes sense, and any help will be greatly appreciated. Thanks in advance.

[jlmuncie]

If the cable is slack but it will not shift to the smallest cog then it may be a limit issue. Try backing out the high limit screw slowly while pedaling until it shifts to the cog.

[e_lasman]

Switch to the lowest gear on shifter, loosen bolt which keeps cable on derailleur, strain cable and tighten the bolt. Don't forget to screw in adjusting bolt unit on shifter and then loosen for 5-7 "clicks".
This is normal if bike is somewhat ridden — cables are metal and tend to stretch by time. Or maybe bolt wasn't properly tighten on derailleur.

[J.B. Weld]

cables are metal and tend to stretch by time..

Not really, but ferrules can seat on the housing and into the cable guides. Brake cable housing can also compress somewhat. If the OP is talking about the rear cog then either the high limit screw needs backed out or the derailleur hanger is bent inward.

I'm betting on the hanger.

[das028]

Its actually the front cogs, the "granny gear". Im pretty sure, almost positive, jlmuncie hit the nail on th head. Being new, and obvisiously ignorant, I was looking over my bike the other day before I went out and noticed the 2 limit scews (didnt know what they where for) had backed out some....so like an idiot I decided to screw the back in...haha...I figured they had backed themselves out somehow from vibration or somthing...I'm a noob fellas...take it easy on me

So anyways, is there a trick or a certain way I should set theses back, or do it just by feel? I figured when I'd fix them saturday before I ride...Oh and thanks for the help guys!

[eatdrinkride]

So anyways, is there a trick or a certain way I should set theses back, or do it just by feel? I figured when I'd fix them saturday before I ride...Oh and thanks for the help guys!

No trick, but there is a proper adjustment needed. It's very simple, simpler than text makes it seem.

In your case you can skip most of it and just jump down to the limit screw adjustments for the front der. in this article.

Derailer Adjustment

[e_lasman]

Here is one more with the video guide

[TiGeo]

Sounds like your limit screw needs to be adjusted.