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I have a touring bicycle with 3 x 9 gears. The front derailleur and front shifter are Shimano Sora. Some time ago, the front derailleur started skipping the middle chain ring when downshifting from the largest chain ring. When doing just one downshift click, the front shifter and derailleur goes all the way to “smallest chain ring position”, and I have to upshift twice if I want to go back to the largest chain ring.

I have flushed the front shift lever approximately 5 times with degreaser and WD-40 and then re-lubricated to get rid of any gummed up grease. It solved the problem for a while but now it is back. Flushing and re-greasing does not help anymore.

I have also replaced the inner gear cable without any luck.

I have cleaned and lubricated the front derailleur mechanism.

I have adjusted the cable tension on the front derailleur, so it works well (no chain rub when on middle chain ring no matter which sprocket on cassettte I am on).

If I release the gear cable from the front derailleur and mimic cable tension by pulling the cable with my hand, I can feel the front shifter stopping in the middle chain ring position when downshifting from largest chain ring position. Meaning, the front shifter seems to work as it should when I pull the cable by hand. When I reinstall the cable on the front derailleur, the front shifter starts skipping middle chain ring position again when downshifting.

In general, I use the front shifter a lot - I like shifting gears quite frequently, and not only on the cassette.

Any ideas as to what I should do?

My next step will probably be to buy a new front derailleur because I am out of ideas and because I read somewhere about a guy who solved a similar problem by replacing the front derailleur.

I added some photos of my chain rings. I don't know if the teeth are worn to a degree where this could be part of the problem.

Large and middle chain ring from seen from non-drive side

Large chain ring seen from drive side

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  • Do you shift at the chainrings a lot ? Personally I change at the rear hundreds of times and only change the front when doing a climb, so the right-hand/rear shifter will wear much faster, and the left/front shifter wears far less.
    – Criggie
    Commented Feb 22, 2023 at 22:49
  • Yes, I shift at the chain rings a lot. I edited my post to add this info (thanks for asking) Commented Feb 23, 2023 at 5:21

4 Answers 4

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Front Derailleur is a pretty simple mechanical device and unlikely the cause of the problem. It is possible that it is not setup correctly and replacing it would end up with the new one working, not because of the replacement, but because the setup problems were corrected.

From the description, the most likely cause of the problem is the shifter has worn and when dropping from big chain ring the rachet mechanism is not stopping on the middle ring. The flush and re-lube helped for a while by improving the speed of the ratchet, but the wear is now at a point it will not engage even after fresh clean and lube. The most likely successful fix will be a new shifter.

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  • Concur - the derailleur works as expected when pulling exposed inner, therefore the problem is in the shifter. PO might replace the brifter, or simply add another three-position shifter, maybe as a bar-end shifter or a downtube or stem shifter and leave the left-hand brifter as a brake-lever only.
    – Criggie
    Commented Feb 22, 2023 at 22:51
  • OP is saying they feel the detent of the middle position at the shifter when tensioning the inner cable by hand and manipulating shifter. Not that it couldn't still be worn and failing under what's likely more cable tension than can be easily put on by hand. In a set-up otherwise correct, Shimano suggests loosening the barrel adjuster a turn or two (increase cable tension) when the middle ring is skipped coming down from the large. Also be aware the position of the derailleur inner cage should be less than 0.5mm from the chain when in middle ring-large cog. More gap may cause over shift.
    – Jeff
    Commented Feb 26, 2023 at 12:31
  • I have now replaced the shifter with a similar, new unit, and it immediately resolved the problem. Thanks for your input! Commented Apr 15, 2023 at 4:39
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I would be inclined to complete a front derailleur set-up from the beginning before giving up on either of the components. Often times when one starts messing with a front derailleur that's already set-up in order to correct a problem, the maneuver to correct the problem in one area causes trouble in another. This is why I stress to start from scratch: release cable from the pinch bolt and begin checking the height and alignment of the cage relative to the large chainring.

The outer cage should be about 2mm above the teeth of the large chainring and the flat, lateral surface of the outer plate should be parallel to the outer surface of the chainring. A good test to check this is by taking an Allen key, placing a flat side of the long portion on the flat outer aspect of chainring right under the teeth. Have the long end of the wrench sticking out from the chainring enough so that it rubs along the outer cage plate of the derailleur. Your essentially projecting the plane of the outer chainring with the Allen key so that you can compare it with the outer cage plate. As you rotate the chainwheel/wrench, it should brush along the outside face of the outer cage. You can also check that the rotation of the derailleur is aligned properly: the Allen key should maintain it's position relative to the cage plate throughout the sweep of the cage length. To correct for any gap or a cage outside the plane of the chainring, manipulate the derailleur's L limit screw. Rotational adjustment, if necessary, can be done by loosening the clamp bolt and rotating the derailleur or loosening the fixing bolt of a braze on setup which will give you some minimal rotational adjustment. Be careful not to change the height of the derailleur from it's 2mm gap above the chainring teeth.

The low limit of the derailleur is set with the chain on the small chainwheel and large cassette cog. The goal is to position the derailleur JUST enough to the inside to prevent chainrub on the inner cage plate in this gear combination. I usually turn the cranks and slowly tighten the L limit screw until I hear chainrub, then slowly loosen it until the noise just disappears. Usually not more than a ¼ turn.

The inner cable can now be tightened and fixed under the bolt. Pay attention that the cable is routed thru the pinch bolt area correctly--especially that it comes across any leverage tabs on its way to the pinch bolt. Often the front der set up is fouled by a missed leverage tab and shifting is difficult or excess cable tension is required to achieve acceptable shifting. Check shifting to the middle and large chainrings.

Next set the H limit screw with the chain on the large chainwheel and smallest cog. Here you want the smallest gap between the inner aspect of the outer cage plate and chain--just enough gap so there is no rub. Similar to the L setting, here I turn the H limit clockwise until I hear chainrub then back it off until the noise just disappears.

Final set up is the middle chainring. Here the chain should be on the largest cog in back and, of course, the middle chainring. We manipulate the BARREL ADJUSTER to achieve a setting where there is minimal distance between chain and inner cage plate. Turn the adjuster so that the inner cage makes contact with the chain (clockwise the derailleur moves inward; counter-clockwise causes the derailleur to move outward). When the chain is rubbing, turn the adjuster clock wise until the rub just disappears.

Shimano states that the first thing to try when the intermediate ring is skipped upon shifting from the large ring is turning the barrel adjuster counter-clockwise. This infers the cable is too loose initially. It also infers a front derailleur set-up positioned too far to the inside creating an over shift situation. Each step's positioning of the respective cage plates to the chain effectively sets the workable range for the derailleur. It's easy to get plenty of room between inner cage and the chain in the small and middle ring set-up. No risk of chain rub but there's excessive inward movement of the derailleur causing problems. A millimeter can be excessive here. Similarly a cable route that misses a leverage tab has inappropriate cable tension through the swing of the derailleur, dropping off excessively when the cable is released on the shift from the large ring and causing overshift.

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  • I now did the installation of the front derailleur from scratch. I loosened the band holding the derailleur in place and started by setting cage height and alignment relative to outer chainring. Then adjusted L and H limits. Finally adjusted cable tension. I also made sure cable routing was correct. I followed Shimano's guidelines. I also tried increasing chain tension. Same result: consistently skipping middle chain ring when downshifting from largest chainring. I am going to post some photos of my chainring teeth - I don't know if they are worn out and could be part of the problem Commented Mar 5, 2023 at 7:18
  • I'm sorry. I don't have any more suggestions at the moment. Wear of the chainring teeth doesn't appear to be excessive. Have you checked the chain for stretch?
    – Jeff
    Commented Mar 7, 2023 at 20:33
  • Thanks for commenting on the chain rings. The chain is worn (between .75 and 1 percent). I have now ordered new parts. First I am going to replace the chain (and cassette) to see if it resolves the problem. If not, I am going to install a new front shifter. I have a feeling the new shifter will do the trick. But we will see. Commented Mar 9, 2023 at 17:08
  • I replaced chain and cassette but it didn't resolve the problem. In the end I replaced the shifter with a new unit and it did the trick. Commented Apr 15, 2023 at 4:40
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The end of the outer cable housing can rust and tighten up on the inner cable. New inner cable and lube won't fix this. I would try a whole new cable. Maybe upgrade to a stainless version with Teflon liner. Jagwire and others sell these. The front derailleur is Low normal. It lets out cable for a down shift, and pulls cable for an upshift. So drag in the cable will affect downshifts more than up shifts.

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  • The problem was solved by installing a new front shifter Commented Oct 16, 2023 at 14:21
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The problem was solved by installing a new front shifter. I am not entirely sure what caused the problem in the first place. My best bet is that the old shifter was worn down mechanically to a degree where it was failing. I don't believe the issue was hardened grease as I had tried several time to flush the old shifter with degreaser and then lubricating with spray oil - without any luck.

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  • Good to hear. Could you elaborate on the solution, since you are closest to it? For example, was the old shifter worn? Was the mechanism sticky? Or some other reason. Add at least one or more sentences starting with "The old front shifter was..." It will help complete your question and your final answer.
    – Ted Hohl
    Commented Oct 16, 2023 at 17:49
  • I have now tried to elaborate as much as I can. BTW, I am not entirely sure how I "close" my own question now that I found a solution, so that it is apparent to everyone that the problem was solved Commented Oct 17, 2023 at 19:53
  • You don’t need to close the question. It stays in its current state, so others can learn from your experience.
    – Ted Hohl
    Commented Oct 17, 2023 at 21:00
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    Ok, thanks for the info Commented Oct 19, 2023 at 7:24

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