Gears

[HLaB]

Gears/ Rear Derailleur

The gears on my winter bike have started to slip (down a cog, up a gear) I can adjust this tighten the cable so this doesn't happen and everything changes down (up to the larger cogs) fine. However when I shift up (to a smaller cog) from the largest it takes 2 clicks of the sti. The rest of the cogs change fine but it jumps over the 2nd last to the smallest.
My theory is the spring in the rear derailleur needs some tender care or I need a new one any other ideas?

 

[downfader]

I have a similar problem but my front derailer was out of alignment. Tried to adjust it myself and it went bananas on me. Cant seem to get it sorted...

...still waiting on my new wheels to come in so I can put it in for a full service.

 

[HLaB]

I cleaned an oiled things last night and then as zinn reccomended after tryining the barrel adjuster I loosened the h limit screw it only seemed to shift the problem down a cog or two. It was all new cables 6 months ago and I checked there moving fine. Maybe the deraileur has been damaged by a crash a while back when I replaced the hanger only; I think I'll have to give up and take it to a lbs to ask their advice.

 

[Globalti]

Every 6 months or sooner you need to change the cable outer where it bends round 180 degrees to the derailleur. This is the bit that wears fastest and get clogged with dirt and damp, which produces the symptoms you describe. If you're going to do it yourself, you will need:

Some cable cutters - a good investment for any cyclist.
A metre of gear cable outer.
Some plastic end ferrules.
Some metal inner cable caps.
Why not a new inner cable too? They're cheap.

Put the gears to the smallest cog. Undo the allen bolt holding the cable to the derailleur. Remove the cable end cap taking care not to splay the strands. Pull off the outer. Marvel at how dirty and rusty it's all become. Remove the ferrules and cut a new length of outer roughly the same but as longer if possible to create a bigger radius. Clean the cable with wire wool and run it through fingers lightly wetted with a dry chain lube. Alternatively just fit a brand new cable, following the same route as the old one. Don't lube it, keep it dry and clean.

Get everything arranged as before, not forgetting the plastic ferrules then, tensioning the cable gently with pliers, clamp it behind the L shaped washer, which is held by the allen bolt. Don't overtighten, finger tight is OK.

Wind out the cable adjuster until the derailleur begins to move inwards then test ride. You will need to make a few adjustments to get it registering right. Crimp on a new end cap with the pliers.

You'll be amazed at the improvement in shifting.

If this doesn't work, get your LBS to check the alignment of the derailleur dropout with their special tool. Take the frame and the back wheel along.

 

[HLaB]

Thanks RR , that seemed to have been the problem.