I've stumped the mechanic with my rear shift issue.

Discussion in 'Cycling Equipment' started by Bike4Him, Mar 26, 2014.

  1. Bike4Him

    Bike4Him New Member

    Joined:
    Oct 17, 2009
    Messages:
    105
    Likes Received:
    0
    I have a 2012 Ultegra drivetrain and a 12-27 Ultegra cassette.
    Shifting is great from the big or small ring through the lowest and highest gears.
    In the middle of the cassette I sometimes have to shift twice up or down to get one cog change.

    I can usually just push on the brake lever a little past the "click" to go lower, but then sometimes I go to far.

    Anyway, it's annoying and I can't figure it out.
     
    Tags:


  2. maydog

    maydog Well-Known Member

    Joined:
    Feb 5, 2010
    Messages:
    1,333
    Likes Received:
    90
    I have a few ideas, but I would think that the mech would have checked them:

    Sticky Cables
    Sticky Derailleur
    Worn cassette
    Worn chain
     
  3. CAMPYBOB

    CAMPYBOB Well-Known Member

    Joined:
    Sep 12, 2005
    Messages:
    11,945
    Likes Received:
    1,038
    How old / worn is the shift lever assembly?

    I'm with maydog. First thing I would look at would be the cables. Second thing I would check is the jockey pulley.
     
  4. danfoz

    danfoz Well-Known Member

    Joined:
    Apr 12, 2011
    Messages:
    2,432
    Likes Received:
    92
    What those guys above said and...

    Are you sure it's both ways you have to occasionally double shift to get to the next gear? I only ask that as barrel adjustments can get finicky sometimes. The barrel adjusts the indexing, i.e. where the derailleur pulley assembly lies in alignment relative to the gears. If not adjusted ideally, it can be riding the chain closer to one of the cassette rings, quicker to shift in one direction and slower to shift in the other because it is slightly (we're talking <.5-1mm) away. If not adjusted correctly it can occasionally require a double shift to get to the cassette ring which is on the slower shift side (thus to correct needing the derailleur pulley ever so slightly closer in the alignment scheme of things to the gear that is slower to shift to). If that's the issue, sometimes a single turn (or less) of the barrel in the appropriate direction can correct.

    Just a thought.
     
  5. oldbobcat

    oldbobcat Well-Known Member

    Joined:
    Aug 31, 2003
    Messages:
    3,233
    Likes Received:
    95
    Two more.

    Bent derailleur hanger
    Misrouted shift cable
     
  6. maydog

    maydog Well-Known Member

    Joined:
    Feb 5, 2010
    Messages:
    1,333
    Likes Received:
    90
    Last one,

    Inept mechanic.


    So did you get this figured out yet?
     
  7. Subliminal-SS

    Subliminal-SS New Member

    Joined:
    Sep 4, 2013
    Messages:
    86
    Likes Received:
    2
    I have this. Driving me Mad Sram Force setup.

    Until recently been a whole gear out to get it to shift but fed up that.

    Summers here though new chain cassette chianrings courtesy of broken PM and its all almost working. Now its just sluggish in the middle of the cassette.

    Checked everything now even got a Hanger tool. Short of the RD spring being tierd (negative of living on a hilltop is that I always have to pullup in the big cassette ring) and not pulling back enough which apparently is highly unlikely I can only think of cables so picked myself up some Yokozuna Cables, will see how they go. Also check the cable guide. I noticed mine has been cut into and I think its providing quite some resistance personally.


    GL
     
  8. CAMPYBOB

    CAMPYBOB Well-Known Member

    Joined:
    Sep 12, 2005
    Messages:
    11,945
    Likes Received:
    1,038
    Can you run a length of housing liner through your cable guide? That should help reduce friction in that area.
     
  9. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    WHAT is the incline of the roadway when the shifting is balky?

    Roughly, how fast-or-slow would you say the bike is moving at the time?
     
  10. Subliminal-SS

    Subliminal-SS New Member

    Joined:
    Sep 4, 2013
    Messages:
    86
    Likes Received:
    2
    Thats a really good idea, may need some hackery but I think I should be able to get it to work. Thanks!
     
  11. Bike4Him

    Bike4Him New Member

    Joined:
    Oct 17, 2009
    Messages:
    105
    Likes Received:
    0
    No.
    I can get it close with the barrel adjuster, but I still have an issue with the middle two cogs.
    I typically have to decide whether I want crisp shifting going higher or lower and then adjust to accomplish that.
    Most times I inadvertently shift twice to go lower and then it shifts like an automatic when I don't expect it.
    The chain is an Ultegra with very little wear.
    The derailleur has about 2,000 miles on it and is clean.
    The cassette might have 3,000 miles on it.
    No, sorry, it's only when I go lower that I sometimes shift twice (or have to shift twice) and then it will shift like an automatic if I don't feel the 2 clicks.
    Winter gloves and I can't always tell.
     
  12. maydog

    maydog Well-Known Member

    Joined:
    Feb 5, 2010
    Messages:
    1,333
    Likes Received:
    90
    I can smoke a cassette in 3K. Generally the middle cogs will have the most wear.

    Is the cassette stack assembled tightly - maybe there is an issue with the spacing.

    I do have a similar issue on my cross bike, but all the components are really worn. To downshift, I have to shift plus an extra bump, half shift, afterward. I am chalking that up a work 2300 shifter.
     
  13. Bike4Him

    Bike4Him New Member

    Joined:
    Oct 17, 2009
    Messages:
    105
    Likes Received:
    0
    The cassette is tight.
    Just pushing the shift lever until it clicks does next to nothing. I have to push it way past the click and then sometimes it goes too far and double shifts.
    There is about 1" movement in the lever before it even begins to engage the cable.
    Here is a link to a video of what the lever does.
    https://www.dropbox.com/s/sq7p9rkbihliwmn/VID_20140409_204310833.mp4
     
  14. oldbobcat

    oldbobcat Well-Known Member

    Joined:
    Aug 31, 2003
    Messages:
    3,233
    Likes Received:
    95
    You have already replaced the cable and housings, and the openings in the housings are open, and the cable loops are nice and round, and there is nothing compressing the cable or cable housing, right? And if the routing is inside the frame, there's no chance that the front and rear cable are crossed? And the cable is correctly routed out the back of the stay, and all housings are firmly seated in their ferrules? And, by the way, shifting is often better if you route the cable around the outside of the handlebar, not the inside.

    Because the problem only presents itself around the middle of the cassette, not the slow end or the fast end, and the spring drops the chain down to smaller cogs promptly (presumably), I'm starting to suspect the lever. Before giving up on it or submitting it for warranty replacement, here's my suggestion. Replace the cable and spray the inside of the shifting mechanism with an aerosol solvent. Let it soak and drip for a few minutes, then work it around by trying a few shifts. Then let it dry, or speed that up with compressed air, and then load it with a foaming aerosol lubricant. Sheldon Brown recommends lithium spray grease.

    If this doesn't loosen up something foreign in there, I'd suspect worn ratcheting splines, which could turn into a warranty case.
     
  15. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    AGAIN, WHAT is the incline of the roadway when the shifting is balky?

    Roughly, how fast-or-slow would you say the bike is moving at the time?

    No offense, but if you cannot be more specific about the conditions other than to say "sometimes" AND if the solutions which have been offered have not pointed you in the right direction, then your query is almost as meaningless as asking whether it will rain on October 14th.

    Quote:
    Originally Posted by oldbobcat .
    You have already replaced the cable and housings, and the openings in the housings are open, and the cable loops are nice and round, and there is nothing compressing the cable or cable housing, right? And if the routing is inside the frame, there's no chance that the front and rear cable are crossed? And the cable is correctly routed out the back of the stay, and all housings are firmly seated in their ferrules? And, by the way, shifting is often better if you route the cable around the outside of the handlebar, not the inside.

    Because the problem only presents itself around the middle of the cassette, not the slow end or the fast end, and the spring drops the chain down to smaller cogs promptly (presumably), I'm starting to suspect the lever. Before giving up on it or submitting it for warranty replacement, here's my suggestion. Replace the cable and spray the inside of the shifting mechanism with an aerosol solvent. Let it soak and drip for a few minutes, then work it around by trying a few shifts. Then let it dry, or speed that up with compressed air, and then load it with a foaming aerosol lubricant. Sheldon Brown recommends lithium spray grease.

    If this doesn't loosen up something foreign in there, I'd suspect worn ratcheting splines, which could turn into a warranty case.


    GEEZ ...
    While it certain could be a warranty issue, the shifter is only 1+ year old ...

    Time to consider CAMPAGNOLO SHIFTERS!!! [​IMG]

    Of course, THAT comment is to lighten-the-mood after my chastising the OP for his/her ridiculously vague description of the problem ...

    But, first ...

    The OP needs to try to confirm that the problem is NOT the Cassette by swapping the current wheel with another & isolate each component, individually.

    THAT also means that the OP should have someone else try the particular wheel/Cassette on another bike.

    ALSO, when the problem occurs, then s/he should turn around and replicate the "moment" by riding across the same roadway AND executing the same shift, again.
     
  16. oldbobcat

    oldbobcat Well-Known Member

    Joined:
    Aug 31, 2003
    Messages:
    3,233
    Likes Received:
    95
    I knew you'd say that.
     
  17. danfoz

    danfoz Well-Known Member

    Joined:
    Apr 12, 2011
    Messages:
    2,432
    Likes Received:
    92
    +1!
     
  18. CAMPYBOB

    CAMPYBOB Well-Known Member

    Joined:
    Sep 12, 2005
    Messages:
    11,945
    Likes Received:
    1,038
    Sweet Lincoln welder and do I see a Makita box hanging on the wall?

    And yeah...the answer is always, "Moar Campy shifters!". And Campy derailleurs. And Campy cassettes and cranksets...

    FWIW, I'm with Maydog on the roaching a cassette/chain issue. I'm no Hi-Watt killer, but I can still wear out chains and cassettes with a frequency that keeps a credit card smoldering.
     
  19. oldbobcat

    oldbobcat Well-Known Member

    Joined:
    Aug 31, 2003
    Messages:
    3,233
    Likes Received:
    95
    If I had the bike in my stand I'm sure I'd at least be able to name the culprit. There are some things you just have to see and feel for yourself.

    Have you tried taking it to a different shop? That might still be cheaper than switching the whole thing over to Campagnolo.

    One last question. If you're using one of Shimano's 10-speed directional chains, is it going in the right direction?
     
  20. PingPing

    PingPing New Member

    Joined:
    Mar 23, 2014
    Messages:
    3
    Likes Received:
    0
    Hi Bike4Him, try oiling (light Teflon oil or Cable Magic oil or even Machine oil to try) the cable where it goes through the BB (Bottom Bracket) guide.
    Sometimes, the shift cable can drag a little as it goes through the BB guide channel... [​IMG]
     
Loading...
Loading...