Bicycle Mechanics - rd adjustments

When I'm shifting from the third smallest cog in back to the second smallest cog, the rear derailleur fails to shift most of the time and makes this awful ratcheting noise. Sometimes, it will work, but only after a few seconds of spinning. The other gears are fine, although the downshifts on the smaller cogs tend to be more clunky, which is sort of counter-intuitive. This only happens when riding and not so much on the stand. Should I tune with the barrel adjusters or touch the L-H settings? THanks

When I'm shifting from the third smallest cog in back to the second smallest cog, the rear derailleur fails to shift most of the time and makes this awful ratcheting noise. Sometimes, it will work, but only after a few seconds of spinning. The other gears are fine, although the downshifts on the smaller cogs tend to be more clunky, which is sort of counter-intuitive. This only happens when riding and not so much on the stand. Should I tune with the barrel adjusters or touch the L-H settings? THanks

Barrel adjuster. It sounds like it needs to be screwed in a little bit. Also, there may be something in the cable or cable housing that's hanging up- how long has it been since you lubed the cables?

Most likely the housing. Second guess is a faulty derailleur. (I am assuming it shifts to progressively larger cogs just fine)

To shift to the smaller cogs, the shifter just releases tension a bit (one ratchet worth). The cable could be getting hung up in the housing for a few seconds.

BTW, the L&H screws have nothing to do with this, they just set the limits on derailleur travel.

agreed with thomson, try lubing your cables or get a new cable and houseing, if that doesn't work then your derailleur may have a weak spring so its not pulling over as forceful as it was when it was new

All good replies so far.

Add to the mix: derailleur hanger alignment.

Add to the mix: derailleur hanger alignment.

+2 :thumb:

Replace shifter cables each year. And new cable-housing as well. Add a little oil - not grease - to the insides of the new housing, and wipe some on the new cable as well.