Not enough movement in the front derailleur

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  • Not enough movement in the front derailleur
  • ppapa
    Member

    Yes, there are still people non-1x :(. I’ve got 2×10 (SLX shifters, Deore FD and XT RD) setup. The bike is only few months old.

    After messing a bit too much with the gears, I managed to get the front derailleur work pretty well, shifting back and forth. However, I have rubbing in either extreme end: innermost or outermost cogs (as in, smallest front and largest rear and vice versa).

    Both limit screws allow enough movement in either side. If I tighten the cable more by adjusting the barrel in the shifter, then it rubs the chain when on the smaller cog. If I slacken it, then it either does not move enough to shift or rubs terribly on the larger cog.

    The chain seems to be parallel to the shifter cage and there’s a 3~4mm vertical gap between the cage and outer cog.

    HELP?!

    Premier Icon ampthill
    Subscriber

    However, I have rubbing in either extreme end: innermost or outermost cogs (as in, smallest front and largest rear and vice versa).

    I would usually work on the basis that both of those gears would never work without rubbing. I’d change at the front to avoid the issue

    Other opinions may vary

    Premier Icon BadlyWiredDog
    Subscriber

    Are you sure it’s not a single-ring mech?

    Premier Icon kayak23
    Subscriber

    Of course if this were a 1x thread talking about problems with indexing, then someone would be along in no time to tell us that 2x is perfection and that shifting is crisp and faultless and has been for the last forty years and that all of us on 1x are just gullible fashion victims who’ve fallen for the trap set by the industry marketeers….

    So yeah, thanks for restoring some balance 😉
    😀

    trail_rat
    Member

    What is the full model number of the front mech

    Double.mechs are different to triples

    Same for cranks. A proper double crank has a different chain line to a triple with a ring removed

    scotroutes
    Member

    Kayak23 wrote:

    Of course if this were a 1x thread talking about problems with indexing, then someone would be along in no time to tell us that 2x is perfection and that shifting is crisp and faultless and has been for the last forty years and that all of us on 1x are just gullible fashion victims who’ve fallen for the trap set by the industry marketeers….

    Not at all. I’ve often pointed out that 1x is favoured by the mechanically inept and those that can’t co-ordinate two thumbs.

    ppapa
    Member

    I’d love to go 1x for the obvious reasons (rode single speed/fixed commuter for quite few years), but I’d rather get a dropper post first.

    What is the full model number of the front mech

    Double.mechs are different to triples

    Same for cranks. A proper double crank has a different chain line to a triple with a ring removed

    It’s a stock set-up, so would imagine they didn’t fail that one…
    Front Derailleur
    Shimano Deore FD-M618-L / 34.9
    Chain set
    Shimano FC-M627 2-piece Design 900 Series: 36×22 T
    Chain
    KMC X10
    Shifters
    Shimano SLX SL-M670 Rapidire plus / 2 way release w/gear indicator

    Premier Icon simondbarnes
    Subscriber

    However, I have rubbing in either extreme end: innermost or outermost cogs (as in, smallest front and largest rear and vice versa).
    I would usually work on the basis that both of those gears would never work without rubbing. I’d change at the front to avoid the issue

    Very much this

    ppapa
    Member

    Thanks, will need to decide whether I use the lowest or highest gear more often.

    Premier Icon kayak23
    Subscriber

    Not at all. I’ve often pointed out that 1x is favoured by the mechanically inept and those that can’t co-ordinate two thumbs.

    Oh you guys…. 😆

    coatesy
    Member

    Apart from the avoiding running in extreme gears thing, it may be worth checking which shift mode your shifter is in as 1st to 2nd in 3x will pull a little more cable than the 2nd to 3rd in 2x, so may give you that little extra movement you need.

    Premier Icon garage-dweller
    Subscriber

    Has the mech slipped down or round the seat tube? The cage is shaped to provide extra clearance at the extremes. But if it’s not spot on for height and rotation then it’ll rub.

    Premier Icon garage-dweller
    Subscriber

    However, I have rubbing in either extreme end: innermost or outermost cogs (as in, smallest front and largest rear and vice versa).

    I would usually work on the basis that both of those gears would never work without rubbing. I’d change at the front to avoid the issue[/quote]

    Not being funny but if it’s rubbing in small front, big rear then shifting at the front is not going to be terribly helpful since your only option is to make the gear harder – unless you’re saying the op needs a dose of man up.

    taxi25
    Member

    A bit of rub here or there is irrelevant. Just ride the bike and ignore it.

    Premier Icon ampthill
    Subscriber

    Not being funny but if it’s rubbing in small front, big rear then shifting at the front is not going to be terribly helpful since your only option is to make the gear harder – unless you’re saying the op needs a dose of man up

    Not being funny but if it’s rubbing in small front, big rear then shifting at the front is not going to be terribly helpful since your only option is to make the gear harder – unless you’re saying the op needs a dose of man up.

    I read this as being rubbed when crossed small front small rear. But you are corect it doesn’t say that does it. But maybe its what the OP meant. I’m clutching at straws now

    ppapa
    Member

    Sorry, I meant that it rubs either on the lowest gear (small front and large rear) or the highest gear (largest front and smallest rear). I can adjust the tension so that it does not rub on the lowest gear, but then the highest gear will rub a bit.

    Good shout re “shift mode”. Will check that out.

    Premier Icon twisty
    Subscriber

    Worth looking at where it is rubbing, it could be rubbing because the mech is twisted a bit rather than being straight.
    Also check how the cable is attached to the mech, the amount of mech movement is dependent on which side of the clamp bolt the cable is going.

    Sometimes it just comes down to deliberately setting the mech a little squint or gently bending the cage in one spot to get rid of the last little bit of rub but the cable clamping, shift mode and height of the mech are worth playing with.

    +1 for front mech height or alignment being the issue.

    khani
    Member

    Did you set the inner stop with the cable disconnected? if not start again and do it with the cable undone, and then connect the cable set the outer stop as normal and then fine tune with cable tension,
    Assuming it’s the right type of front mech..

    votchy
    Member

    The chain seems to be parallel to the shifter cage and there’s a 3~4mm vertical gap between the cage and outer cog.

    The cage should be 2mm above the teeth on the big ring and should also be parallel to the big ring, not the chain.

    votchy
    Member

    Also, have you got the mode selector in the correct position as front shifter can do 3x and 2x?

    ppapa
    Member

    I ended up taking it to a bike shop (boo!). Really wanted to fix it myself, but got one ride long ahead over two days where a failure would be a disaster.

    The cable was a bit too frayed after messing with it, so that was step one. We managed to get it just about right, but also lowered/straightened the mech. Indexed again and somehow ended up changing the shifter mode. The mechanic never worked on a 2x/3x shifter, so at least I could help with that. It’s still a bit magical as now it’s set to “A” mode which I was sure was for 3 chain rings. I tried to look it up online but couldn’t figure out how it works. But it does.

    Great work from The Bike Station in Glasgow. They insisted that it’s £2 for the cable, so ended up buying accessories that I needed. Leaving the shop with £2 spent would have been stealing.

    Good stuff and day saved.

    ppapa
    Member

    Forgot to mention, thanks everyone for suggestions and help. I really appreciate it as I want to learn how to fix things, but the learning curve is a bit steep.

    Premier Icon lunge
    Subscriber

    I would:
    Remove the cable from the front mech.
    Put the chain in the biggest cog at the back.
    Adjust the inner limit screw so that the inner plate of the mech is about 1mm from chain.
    Thread the cable and tighten tension until there is no slack.
    Shift into the big ring at the front and the small cog at the back.
    Check the front mech is about 2-3mm higher than the front cog. If it’s not you may need to adjust and change the tension on the cable again.
    Adjust the limit screw, you want the outer plate about 1mm away from the chain.
    Put the chain into a middle cog at the back and try a few shifts back and forth. You may need to make some minor changes to tension or limit screws but they will only be minor, you should be quite close there.

    For what it’s worth, the pain of adjusting front mechs is only eclipsed by the bad chain line and poor range of 1x systems. However, setting it up is a rare thing, 1x is a pain every ride!

    Premier Icon sillyoldman
    Subscriber

    Is it a side swing mech? They require the shifter to be in 3x mode on 2x set ups.

    ppapa
    Member

    Is it a side swing mech? They require the shifter to be in 3x mode on 2x set ups.

    Nope. It was definitely set up for 2x before and it all worked perfectly until something happened on the Glen Tilt circuit. Realized I can’t shift to an upper cog, started messing with indexing, that didn’t work out. Came back home and messed with it more. It’s all good now :).

    I suppose it was indeed the position of the mech itself or in the worst case frayed cable after I pulled it too many times.

    The only mystery is why the shifter used to show as if I was shifting between 1/2 cogs and now it says as if I was shifting between 2/3 cogs. It works, so I am not going to question anything and taped the switch between 2x/3x as I think I already flicked it too many times while riding.

    dirtydog
    Member

    I meant that it rubs either on the lowest gear (small front and large rear) or the highest gear (largest front and smallest rear). I can adjust the tension so that it does not rub on the lowest gear, but then the highest gear will rub a bit.

    Well that clarifies things and it should work flawlessly in those gears.
    It’s either a setup issue, or possibly, assuming it hasn’t always done this, worn mech pivots, crushed/bent cage.

    Out of interest, has it always done it?

    Edit no it hasn’t, it’s working again, so setup issue 😀

    coatesy
    Member

    Could have just been down to general wear and tear, a little extra play in the mech pivots creating a little extra slack in the mech’s movement, that, in turn, may have needed that little extra cable pull to overcome it that wasn’t required before.

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