Viewing 13 posts - 1 through 13 (of 13 total)
  • Front Mech wont shift down
  • bwfc4eva868
    Free Member

    I don’t know whats u with it. The ride before it was working fine shifted onto all three rings easy enough, shifting from middle to granny ring has always been a bit suspect but it will get there. However I can shift up from Granny ring, to middle and top but once in the top ring it will not shift down at all.

    It feels like there is not tension in the shifter when trying to shift down.

    Its all clean, not been bashed so not sure why its suddenly doing this.

    stevied
    Free Member

    Cables probably full of crap..

    stoney
    Free Member

    Front mechs can be the worst thing to set up on a bike…. Yours sounds like new cable time!.

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    woodlikesbeer
    Free Member

    Try just pulling the cable rather than using the shift lever whilest turning the cranks. This will allow you to feel any friction in the cables. It will also tell you if you have a shifter problem. Cheaper SRAM shifters can have a problem with the spring getting stuck. Ideally you want the bike in a work stand to make it easier.

    If the cable is ok I would suggest looking at the height of the mech. I’ve seen so many bikes come out the box with the mech far too high. You want the cage to clear the top ring by about 2mm. Any more and it won’t drop down properly.

    bwfc4eva868
    Free Member

    Cable looks slack on the downtube as in flapping about. If I click the shifter down it wont move to the middle ring, but if I push the mech with my thumb it then shifts down. Bit of mud in there but the bike was clean when this problem started.

    Shifts up perfectly fine.

    oldgit
    Free Member

    Four riders had the same last Sunday. Wash out, clean with brush and cleaner, wash out then lube.
    They sometimes just don’t return because they’re full of grit and grime.
    Mine didn’t a few hours ago just before cleaning, fine now.

    cdoc
    Free Member

    Both my and a friends xt f mechs do this. A bit of gt85 or similar on all the pivots and the spring and then work it back and forth by hand.

    Seems to solve it for a while.

    midlifecrisis
    Free Member

    In addition to making sure that the pivots are all lubed, it can be worth checking that there is not a small stone / twig jammed in anywhere.

    Does the mech move to the innermost position if you push it across by hand (when the cable has been released and is slack as described above)?

    firestarter
    Free Member

    Bizarrely ive had this with 2 bike builds ive recently done it was fixed by slackening off the front mech cable a bit. I had it a bit too tight and for some reason it wouldn’t shift down properly and when it did it was a right clunk

    Fat-boy-fat
    Full Member

    Had the same thing recently myself. The pivots had totally seized. I had to use loads of penetrating lube to get it moving. It looks like all the grease in the pivots had washed out over time. Mate in a bike shop reckons there’s no way to regrease it well and it’ll just do the same again unless I keep on with loads of the penetrating grease. I think I’ll end up getting fed up with that and it’ll be new mech time. Still, 5 years on this mech isn’t too bad.

    bwfc4eva868
    Free Member

    Gonna give it a spray and quick clean see if that helps. Shouldnt be knackered already as the bikes done 253 miles since I got it in 2013. Mind you it is a acera!

    midlifecrisis
    Free Member

    bikes done 253 miles since I got it in 2013.

    This would suggest that it is the pivots and they have seized up a bit. Lots of spray on them and move the mech through its range of movement by hand.

    You might want to check the cables are still running freely, if not either a bito of lube on them or replace them.

    martinhutch
    Full Member

    Gunk.

    Release the cable, push it backwards and forwards repeatedly by hand while spraying something lubey into the pivots. Eventually it may get its springiness back.

    As midlife has just said, basically.

Viewing 13 posts - 1 through 13 (of 13 total)

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