Indexing gears without removing cable

Hi everyone, I'm not the most mechanically savvy rider. I have a 2021 Giant Defy 1, and the rear gear tend to slip every now and then, especially between gear 3 and 4. Otherwise it shifts ok. Is it a cable tension issue, or an indexing one? I have searched online and every method to set the shifting includes removing the cable first, setting the limit screws etc. Can I index the gears without having to remove the cable? I have a phobia of removing the cable (tried it with my previous bike and it was such a mess..). Thanks for the help! S

Comments

  • elbowloh
    elbowloh Posts: 7,078
    If the bike was properly set up in the first place, you should pretty much never need to touch the limit screws again on that mech.

    So yes, it probably needs a half turn (or whole turn) here or there of the barrel adjuster. You do not have to remove the cable. Most bikes need a bit of a tweak 6 months or so after first use as the cables stretch with use.

    BTW, a cable tension issue is an indexing issue, as indexing (once the limits have been set) is just a matter of adjusting the cable tension.
    Felt F1 2014
    Felt Z6 2012
    Red Arthur Caygill steel frame
    Tall....
    www.seewildlife.co.uk
  • Ncovidius
    Ncovidius Posts: 229
    edited September 2021
    The cables don’t really ‘stretch’ per se ( certainly not by any significant enough amount, with general use to cause significant indexing issues ) what does happen, is that the inners ‘scratch up’ the lining of the outers slightly with use, and the tolerances between inner and outer changes a bit, also bits in the mechanisms change slightly with usage. As mentioned above, You should be able to stop the skipping you’re getting by tweeking the in line barrel adjusters in the gear cables slightly. There should be no need to touch the limit screws ( as they are for setting high and low mech position limits, not for general indexing ). Of course, cables do wear out, with usage, and it’s sensible to change inners and outers at the same time, when they do wear out.
  • elbowloh
    elbowloh Posts: 7,078
    Ncovidius said:

    The cables don’t really ‘stretch’ per se ( certainly not by any significant enough amount, with general use to cause significant indexing issues ) what does happen, is that the inners ‘scratch up’ the lining of the outers slightly with use, and the tolerances between inner and outer changes a bit, also bits in the mechanisms change slightly with usage. As mentioned above, You should be able to stop the skipping you’re getting by tweeking the in line barrel adjusters in the gear cables slightly. There should be no need to touch the limit screws ( as they are for setting high and low mech position limits, not for general indexing ). Of course, cables do wear out, with usage, and it’s sensible to change inners and outers at the same time, when they do wear out.

    Indeed, but it's called cable stretch in the vernacular, much like "chain stretch".
    Felt F1 2014
    Felt Z6 2012
    Red Arthur Caygill steel frame
    Tall....
    www.seewildlife.co.uk
  • Thanks for the help. I'll give a gentle turn to the barrel adjuster and see how that works. Thanks also for clarifying, I know I should get better at maintenance :)
  • mully79
    mully79 Posts: 904
    Barrel adjusters are at the shifter end so that you can adjust while riding.
    Since 1x drive trains came out I reckon they need slight tweaking as the weather gets colder/hotter
  • elbowloh said:

    Ncovidius said:

    The cables don’t really ‘stretch’ per se ( certainly not by any significant enough amount, with general use to cause significant indexing issues ) what does happen, is that the inners ‘scratch up’ the lining of the outers slightly with use, and the tolerances between inner and outer changes a bit, also bits in the mechanisms change slightly with usage. As mentioned above, You should be able to stop the skipping you’re getting by tweeking the in line barrel adjusters in the gear cables slightly. There should be no need to touch the limit screws ( as they are for setting high and low mech position limits, not for general indexing ). Of course, cables do wear out, with usage, and it’s sensible to change inners and outers at the same time, when they do wear out.

    Indeed, but it's called cable stretch in the vernacular, much like "chain stretch".
    Yes indeed, and for pretty similar reasons really. ‘Chain stretch’ is caused by wear to the bushings and rollers, which means they effectively move apart under load, which is effectively a stretch, but the side plates don’t elongate, which confuses people sometimes. The cable ‘stretch’ is pretty much the effect of the slight thinning of the inner cable and the sleeve inside the outer. So not too dissimilar really, and both chain and cable ‘stretch’ can be minimised by keeping everything nicely cleaned and lubed.
  • imposter2.0
    imposter2.0 Posts: 12,028
    Ncovidius said:

    elbowloh said:

    Ncovidius said:

    The cables don’t really ‘stretch’ per se ( certainly not by any significant enough amount, with general use to cause significant indexing issues ) what does happen, is that the inners ‘scratch up’ the lining of the outers slightly with use, and the tolerances between inner and outer changes a bit, also bits in the mechanisms change slightly with usage. As mentioned above, You should be able to stop the skipping you’re getting by tweeking the in line barrel adjusters in the gear cables slightly. There should be no need to touch the limit screws ( as they are for setting high and low mech position limits, not for general indexing ). Of course, cables do wear out, with usage, and it’s sensible to change inners and outers at the same time, when they do wear out.

    Indeed, but it's called cable stretch in the vernacular, much like "chain stretch".
    Yes indeed, and for pretty similar reasons really. ‘Chain stretch’ is caused by wear to the bushings and rollers, which means they effectively move apart under load, which is effectively a stretch, but the side plates don’t elongate, which confuses people sometimes. The cable ‘stretch’ is pretty much the effect of the slight thinning of the inner cable and the sleeve inside the outer. So not too dissimilar really, and both chain and cable ‘stretch’ can be minimised by keeping everything nicely cleaned and lubed.
    Strop trying to sound as though you know what you're talking about. There used to be a time when you claimed that cables did actually stretch.
  • mully79 said:

    Barrel adjusters are at the shifter end so that you can adjust while riding.

    Are you sure that's right? My road bikes have adjusters on the down tubes, as well as the rear derailleur having one as well. My bikes are several years old though, so maybe there are now shifters available with barrel adjusters?
  • elbowloh
    elbowloh Posts: 7,078

    mully79 said:

    Barrel adjusters are at the shifter end so that you can adjust while riding.

    Are you sure that's right? My road bikes have adjusters on the down tubes, as well as the rear derailleur having one as well. My bikes are several years old though, so maybe there are now shifters available with barrel adjusters?
    It's different depending on the manufacturer. I have had bikes near the levers and others on the down tubes.
    Felt F1 2014
    Felt Z6 2012
    Red Arthur Caygill steel frame
    Tall....
    www.seewildlife.co.uk
  • webboo
    webboo Posts: 6,087
    You don’t get adjusters on the shifters they are on the cables half way between the down tube stops and where your cables come out of the bar tape. Usually in front of the head tube.
  • mully79
    mully79 Posts: 904
    sorry, I forgot this is the road forum. MTBs have had adjusters at the levers since the early 90’s
  • imposter2.0
    imposter2.0 Posts: 12,028
    Some of the earlier, lower end sti levers (the ones with the cables coming out the sides) had adjusters at the lever ends. I had a pair once..
  • elbowloh
    elbowloh Posts: 7,078
    webboo said:

    You don’t get adjusters on the shifters they are on the cables half way between the down tube stops and where your cables come out of the bar tape. Usually in front of the head tube.

    Again depends on the bike and the kit you have.
    Felt F1 2014
    Felt Z6 2012
    Red Arthur Caygill steel frame
    Tall....
    www.seewildlife.co.uk
  • webboo
    webboo Posts: 6,087
    Best bike has one on front mech cable. Second best bike has them on both. Winter bike has a little lever thing on down tube stop that increases or decrease cable tension on rear mech cable. Front mech cable has a adjuster on the stop like you get on your rear mech.
  • hold the adjuster and turn the bike.