Shifting problems

_Brun_

I'm having problems getting the rear derailleur to drop down onto the smallest cog, and was hoping some help from here might save me a trip to the LBS.

The indexing seems ok and the limit screws are fine, but one thing I noticed is that the shifter doesn't click when trying to change from 7th to 8th, and the index display only moves about half way towards 8. It does however click when I shift back to 7th again.

The rear mech all seems to move freely enough, so I was wondering if this is likely to be a cable problem (it does look a bit messy at the back end) or possibly something gone wrong in the shifter itself?

Any hints or advice much appreciated

John C.

Sounds like an adjustment problem , when in top is the cable tight or slack, if slack the adjuster needs loosening, if tight it may need slackening, although if the other gears are shifting OK this seems unlikely.

Monty Dog

If you're happy that adjustments are OK, it's probably down to a 'sticky' inner cable, kinked outers or less likely, weak return spring in the rear mech. If possible, give the mech a good clean e.g. toothbrush on the inside of the parallelogram. Check that the exposed sections of the inner cable are clean and not frayed - particularly under the BB - replace the inner if necessary and check the conditions of the outer and that it's not kinked or corroded at the ends/frame stops

bill57

I had the same problem once, it was the final outer cable that was at fault. (The 8 or 9 inches betweeen the chainstay stop and the derailleur itself). This piece catches all the worst of road crud, spray etc. Replacing this fixed my problem; probably better to replace the whole inner as well if this is whats causing it.

_Brun_

Cheers for the replies lads.

I must confess that even though this was posted in the road bike forum, my ride is a dirty hybrid and the cable is therefore fully sheathed from the bars, under the top tube and down to the rear axle.

I gave the rear mech a decent once over the other night, and couldn't see any problems there - it takes very little force to manually coax the chain to drop onto the smallest sprocket. Will see if I can scrub up the cable where it enters the derailleur, and if that doesn't work, replace it.

nicklouse

dont bother trying to clean the cable, if it has been on for a while get both the inner and outer changed.