R7000 rear mech cable route (warning - potentially difficult content)

thistle_
thistle_ Posts: 7,121
edited April 2021 in Workshop
Ok, what have I done wrong here, apart from possibly forking out for a new much that doesn't fit my frame?

Previous mech was a 5800 and worked fine. The new R7000 has moved the barrel adjuster higher up so there's a really tight bend in a really short length of cable outer, and I can't shorten it much more.
Do I need to take a dremel to the ferrule in the barrel adjuster?

The only way I can get it to shift through all 11 gears is to clamp the cable like this, otherwise on the smallest cog the cable is too tight against the cable hole to allow the mech to shift (it will move if I pull it by hand). This looks totally wrong, and there's a lot more force needed to shift onto the bigger cogs with the cable this way.


Any suggestions welcome, including hammer/fire/over the fence.
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Comments

  • elbowloh
    elbowloh Posts: 7,078
    It looks weird, like the whole mech should be twisted about 30 degrees clockwise. Is it seated correctly against the little lip of the dropout or is it supposed to be on a hanger?
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  • thistle_
    thistle_ Posts: 7,121
    elbowloh said:

    It looks weird, like the whole mech should be twisted about 30 degrees clockwise. Is it seated correctly against the little lip of the dropout or is it supposed to be on a hanger?

    It is seated on the lip of the hanger as per the instructions I found on YouTube.
    There are two pins on the link and I've used the upper one. I can try the other one and see, it didn't look right when I tried that position without the cable in place.
  • johngti
    johngti Posts: 2,508
    I'm with elbow - looks like its not mounted correctly
  • thistle_
    thistle_ Posts: 7,121
    Hmm
    I'll have another go at it when I get a chance and see if it can be repositioned.
  • veronese68
    veronese68 Posts: 27,252
    Does look like it's sitting a bit funky. Not having played with one I can't be sure, but in the second picture if the cable went the other side of the clamp bolt it might have more leverage making shifting easier.
  • thistle_
    thistle_ Posts: 7,121

    Does look like it's sitting a bit funky. Not having played with one I can't be sure, but in the second picture if the cable went the other side of the clamp bolt it might have more leverage making shifting easier.

    Running the cable on the other side of the clamp bolt is the correct way to do it and the shifting is lighter, but then I can only shift into 10 out of 11 gears because the cable's pulled so tight against the side of the hole that the friction stops it moving.

    I'll see if i can reposition the mech, might solve everything.
  • me-109
    me-109 Posts: 1,915
    Have you tried removing the extra drop link/direct mount thing? Is that possible? Would that help the cable run?
  • thistle_
    thistle_ Posts: 7,121
    me-109 said:

    Have you tried removing the extra drop link/direct mount thing? Is that possible? Would that help the cable run?

    Instructions say the drop link is needed if you're attaching to a mech hanger.
    You might be able to turn the link though, I can have a look at that.
  • wongataa
    wongataa Posts: 1,001
    thistle_ said:

    elbowloh said:

    It looks weird, like the whole mech should be twisted about 30 degrees clockwise. Is it seated correctly against the little lip of the dropout or is it supposed to be on a hanger?

    It is seated on the lip of the hanger as per the instructions I found on YouTube.
    There are two pins on the link and I've used the upper one. I can try the other one and see, it didn't look right when I tried that position without the cable in place.
    Why are you following installation instructions from YouTube instead of the freely downloadable ones from Shimano? I would follow the manufacturer's installation instructions because they should be correct.
  • thistle_
    thistle_ Posts: 7,121
    wongataa said:

    thistle_ said:

    elbowloh said:

    It looks weird, like the whole mech should be twisted about 30 degrees clockwise. Is it seated correctly against the little lip of the dropout or is it supposed to be on a hanger?

    It is seated on the lip of the hanger as per the instructions I found on YouTube.
    There are two pins on the link and I've used the upper one. I can try the other one and see, it didn't look right when I tried that position without the cable in place.
    Why are you following installation instructions from YouTube instead of the freely downloadable ones from Shimano? I would follow the manufacturer's installation instructions because they should be correct.
    The Shimano instructions say the same as the YouTube video.
  • N0bodyOfTheGoat
    N0bodyOfTheGoat Posts: 5,834
    edited April 2021
    I switched from 105 5800 GS mech to the 105 7000 last summer at the same time as switching from the supplied 11-32 to 11-34 cassette and replacing the rear mech cable that had sheared inside the BRS505 brifter, first time I've messed around with such mech things despite having bikes for decades.

    Internal routing was a bit of a fiddle despite using https://www.amazon.co.uk/gp/product/B07Z4WQY7D , but following the instruction leaflet in the mech box for clamping was fine. I vaguely recall it giving the impression that the cable route through the mech clamp was different to older mech models.
    ================
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  • ugo.santalucia
    ugo.santalucia Posts: 28,172
    Nothing wrong with the angle, it sits high up because the chain is on the smallest sprocket... it should naturally move clockwise as you shift to bigger sprockets
    left the forum March 2023
  • flasher
    flasher Posts: 1,734
    The cable is clamped in the wrong place, it should come straight to the V shaped guide then clamped.


  • thistle_
    thistle_ Posts: 7,121
    flasher said:

    The cable is clamped in the wrong place, it should come straight to the V shaped guide then clamped.

    If I clamp it in the correct position, it won't shift onto the smallest cog. If I clamp it in the wrong place it will :confused:
    I haven't got the end cap with the nose/tongue on at the moment, something to add when I next get a chance to fettle with it.

  • joe_totale-2
    joe_totale-2 Posts: 1,333
    flasher said:

    The cable is clamped in the wrong place, it should come straight to the V shaped guide then clamped.


    This. There's a groove in the clamp which the cable should run through which I can see in photo 2 it isn't right now.
  • i.bhamra
    i.bhamra Posts: 304
    Bigger loop of cable from chainstay to derailleur? The cable exit point at the end of the chainstay is great for an electronic wire, not so good for mechanical shifting efficiency.
  • veronese68
    veronese68 Posts: 27,252
    i.bhamra said:

    Bigger loop of cable from chainstay to derailleur? The cable exit point at the end of the chainstay is great for an electronic wire, not so good for mechanical shifting efficiency.

    I think this might help, read elsewhere about a Shimano mech needing a longer loop than was ideal to allow it to work. Can't remember what the mech was. But if the mech swings forward as it goes through the gears it may need a longer length of outer to enable it to do so.
    Although that may not explain why it wouldn't go into the smallest cog with the cable clamped correctly.
  • flasher
    flasher Posts: 1,734
    thistle_ said:

    flasher said:

    The cable is clamped in the wrong place, it should come straight to the V shaped guide then clamped.

    If I clamp it in the correct position, it won't shift onto the smallest cog. If I clamp it in the wrong place it will :confused:
    I haven't got the end cap with the nose/tongue on at the moment, something to add when I next get a chance to fettle with it.

    You need to follow the instructions, they are there for a reason, you can clearly see the cable rubbing on exit this shouldn't be the case. If you continue like this you will never get clean shifts.
  • i.bhamra
    i.bhamra Posts: 304


    Although that may not explain why it wouldn't go into the smallest cog with the cable clamped correctly.

    I think from the OP's description it could explain it. The force of the short and rigid outer length pushing against the housing on the derailleur is enough to stop the spring pulling the derailleur and chain down on to the last sprocket....it makes sense in my head anyway....
  • If the mech won't go into the smallest sprocket then it's either the stop adjustment or cable tension that is preventing it. The length of cable from frame to mech does look very short so could well be exacerbating the issue.

    If the cable is installed correctly and it won't go to the smallest sprocket then reduce the cable tension. What happens when you remove the cable completely - will the mech shift to the smallest sprocket? If not then it's a stop adjustment issue, if yes then it's cable tension/routing that is the issue or it's just goosed.

    Your issue has taught me one thing today and that is what this word means; Hexalobular
  • i.bhamra
    i.bhamra Posts: 304
    Shimano recommend a specific outer cable for that loop (OT-RS900) which is more flexible and helps with this kind of routing. Personally I just used the same outer I had for the rest of the gear cables with a longer loop. It works perfectly but I also have an older style external mounting point for the outer cable further back down the chainstay.
  • MattFalle
    MattFalle Posts: 11,644

    i.bhamra said:

    Bigger loop of cable from chainstay to derailleur? The cable exit point at the end of the chainstay is great for an electronic wire, not so good for mechanical shifting efficiency.

    I think this might help, read elsewhere about a Shimano mech needing a longer loop than was ideal to allow it to work. Can't remember what the mech was. But if the mech swings forward as it goes through the gears it may need a longer length of outer to enable it to do so.
    Although that may not explain why it wouldn't go into the smallest cog with the cable clamped correctly.
    SRAM cables deffo need a longer cable, must admit to not gaving heard this for Shimano but that cable does look v short.

    I'd extend the cable and see if that helps, a quick double check of limit screws.

    A real curve ball is also to check if the wheel is sitting equally all the way in the drop outs - been known before when people have put wheels in whilst the frame is in a workstand for them not to be seated properly and mech issues to ensue.
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • skeetam
    skeetam Posts: 178
    edited April 2021
    i.bhamra said:

    Bigger loop of cable from chainstay to derailleur? The cable exit point at the end of the chainstay is great for an electronic wire, not so good for mechanical shifting efficiency.


    Firstly, as pointed out by others, the cable is clamped in the wrong place. I can't tell from the picture but Shimano supply a very flexible piece of outer for the tight curve out of the frame to the rear mech. You cannot use normal outer as it won't make that curve without resistance and will push the rear mech in towards the frame.
  • dannbodge
    dannbodge Posts: 1,152
    I've got a box of the proper rear mech cable outers for the Rxxx groupsets (they're super flexible)

    Drop me a PM and you can have one.
  • i.bhamra
    i.bhamra Posts: 304
    edited April 2021
    skeetam said:

    Firstly, as pointed out by others, the cable is clamped in the wrong place.

    Yes. The OP states this is the case in the original post (as well as posting a picture showing this very clearly). The OP also explains why they did it...
  • skeetam
    skeetam Posts: 178
    i.bhamra said:

    skeetam said:

    Firstly, as pointed out by others, the cable is clamped in the wrong place.

    Yes. The OP states this is the case in the original post (as well as posting a picture showing this very clearly). The OP also explains why they did it...
    I’m so glad you’re moderator on this site.

    You incorrectly pointed out that the OP should use normal outer but with a longer loop. With the exit hole on the frame where it is, that will not work. It could work if the exit hole was on the chain stay.

  • pilot_pete
    pilot_pete Posts: 2,120
    edited April 2021



    His setup vs mine. Derailleur looks mounted correctly. My cable exits under the stay which means a much longer, gentler curve in the outer loop. I think the tightness and shortness of your cable outer is the issue - it looks like it’s almost kinking, although the photo is not high enough resolution to see that clearly.

    I’d try the proper ultra-flexible outer first with the cable clamped in the right place. If that doesn’t work, perhaps fitting a noodle to where the inner cable exits the chain stay; the first time where you can see it just to the right of the quick release nut, not after it exits the dropout. A suitable noodle angle may allow a much longer loop of cable outer to overcome that really tight bend.
  • lincolndave
    lincolndave Posts: 9,441
    Any outcome to the problem out yet thistle?
  • seanoconn
    seanoconn Posts: 11,318
    @thistle_ WTF!?

    We need closure
    Pinno, מלך אידיוט וחרא מכונאי
  • MattFalle
    MattFalle Posts: 11,644
    this is triggering me without closure.
    .
    The camera down the willy isn't anything like as bad as it sounds.