R7000 poor rear shifting

g1032
g1032 Posts: 29
in Workshop
Hi folks

Shifting is poor both up and down the block. It works, but often the shift down the block is harsh and clunky and sometime slow. So I'll lessen cable tension and then shifting up the block will be iffy.

I'm looking at the OT-RS900 housing going from chainstay to derailleur and thinking it might be a potential root cause? What do ye think? Does the bend in that cable look too sharp? Could I do with lengthening that?

Last night I installed new outer from shifter to frame. New inner. New ferrules. New cable guide under the BB. No kinks anywhere that I can see. Verified hanger alignment with Park Tool alignment checker and then just for good measure installed a new hanger anyway. Made no difference so went back to original (straight) hanger. Shifter seems fine. Limit screws in correct place. B screw positioned a few mm from cassette when in small/big. It works best with b screw is set so pulley is close to cassette. I'm pretty much at a loss as to why shifting is poor. is that derailleur cable OK do ye think?

I have left the inner uncut at the end so have cable left over if I need to install a longer outer OT-RS900.

Thanks


Comments

  • shirley_basso
    shirley_basso Posts: 6,195
    Is it clamped correctly (read below)

    https://forum.bikeradar.com/discussion/13115581/r7000-rear-mech-cable-route

    Have you watched this?

    https://www.youtube.com/watch?v=ArdlAJ_bhVQ&ab_channel=FreeToCycle

    If it still doesn't work I can only suggest Di2
  • g1032
    g1032 Posts: 29
    :D
    Ya. Clamped correctly. Watched that video yesterday but it didn't tell me anything I don't already know. Derailleur installed correctly (bottom lug as he calls is in contact with the derailleur). Cable clamped correctly also.
  • arlowood
    arlowood Posts: 2,561
    If you've some spare outer lying around then it can't hurt to install a longer loop between chainstay and derailleur. I know with past incarnations of Shimano groupsets it was de-rigeuer to have a sizeable loop at that point to make sure the changes were smooth.
  • MattFalle
    MattFalle Posts: 11,644
    Loop does look tight - pop a longer one on and see what happens.
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • g1032
    g1032 Posts: 29
    Ok. Thanks folks. I can try that later and see
  • lesfirth
    lesfirth Posts: 1,382
    Cable loop is too short but the link bit from the gear hanger to the mech appears to be almost vertical .I think that should be closer to horizontal.
  • g1032
    g1032 Posts: 29
    edited October 2022
    lesfirth said:

    Cable loop is too short but the link bit from the gear hanger to the mech appears to be almost vertical .I think that should be closer to horizontal.

    I don't follow this. Would you please be able to point to that on a screenshot of my picture?

    Edit - Ah, I think this is what you mean. This better? Derailleur in bottom cog position here

  • g1032
    g1032 Posts: 29

    Only after realising that first photo had no wheel in the dropouts :| Cable still too short looking in photo just above???
  • g1032
    g1032 Posts: 29
    Ya. The angle that the cable is coming into the derailleur is certainly different to this stock photo

  • thistle_
    thistle_ Posts: 7,149
    What bike is it?
    I had difficulty getting an R7000 mech to work on my Cannondale which came with a 5800 mech originally.

    There's a thread about it....
  • g1032
    g1032 Posts: 29
    Yup. A Cannondale. What else. Nothing but trouble and never again
  • trevor.hall12
    trevor.hall12 Posts: 416
    edited October 2022
    It does look a bit short and Undo tge RD bolt on the hanger and let it come forward to the stop
  • thistle_
    thistle_ Posts: 7,149
    g1032 said:

    Yup. A Cannondale. What else. Nothing but trouble and never again

    Here you go:

    Dunno what shifters you have, but if they're hydro disc brake ones then check the cable guide in the shifter isn't worn through.
  • g1032
    g1032 Posts: 29
    trevor.hall12 said:

    It does look a bit short and Undo tge RD bolt on the hanger and let it come forward to the stop

    Ya. It's at the hard stop.
  • g1032
    g1032 Posts: 29
    That cable looks really short. Does that work well for you?
  • thistle_
    thistle_ Posts: 7,149
    g1032 said:

    That cable looks really short. Does that work well for you?

    It works fine for me. Maybe try it with an offcut first.
    The R7000 mech doesn't hinge in the same way as the 5800 so a longer loop of outer should be OK as long as there is no kink in it.
  • lesfirth
    lesfirth Posts: 1,382
    g1032 said:

    lesfirth said:

    Cable loop is too short but the link bit from the gear hanger to the mech appears to be almost vertical .I think that should be closer to horizontal.

    I don't follow this. Would you please be able to point to that on a screenshot of my picture?

    Edit - Ah, I think this is what you mean. This better? Derailleur in bottom cog position here

    That's better. You need a " Dura-Ace R9100 Rear Mech Outer Cable Housing" .
    It is much more flexible than standard outer cable.
    Make sure your "B" screw is adjusted to give about 5mm between jockey wheels and cassette in big sprocket.


  • g1032
    g1032 Posts: 29
    I think that's the flexi cable I have? It's OT-RS900

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