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How often do you change your mechanical gear cable sheaths?

neebneeb Posts: 4,362
edited September 2016 in Road general
Just changed the outers on my best bike and had forgotten just how much of a difference it can make.. I'd been thinking that the inferior shifting on this bike compared to my steel bike (which has external cables) was just down to the internal routing, but new cabling has completely transformed the shifting, it's like night and day.

You know when you''re always trying to find the sweet spot in the cable tension where both up and down shifts are snappy, and you just can't get there? And also shifts to the larger sprockets seem to take more effort than they should? That's the sign that something's wrong with the cabling, no modern mechanical system should have those issues. I know that of course, but I always seem to forget it as the shifting quality gradually deteriorates over time...

So, how often (or after how many miles) should you completely change the cable system?

I'd actually been wondering about going electronic until I changed the cables last night, but I'm now reminded that a properly maintained mechanical shifting system is effectively just as good. It's just keeping it that way that's the problem! :)


  • How long is a piece of string?

    I had my Scott CR1 about 5 years and only recently changed the cabling, inner and outer for both gears and brakes.
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  • cougiecougie Posts: 22,512
    As above. Maybe every five years if I'm being good. Usually longer.
  • neebneeb Posts: 4,362
    Yes, I'd probably left it about the same amount of time.. Had changed the inner cables a few times maybe, but had kept the outers. But I think what happens is that the low friction liners inside the sheaths eventually wear out or get contaminated, and it really affects the shifting quality. But it happens gradually, so you don't notice... Maybe there's a random element to it, but in my case it just made a huge difference. Kicking myself for not doing it sooner!

    I wonder how much of the perceived advantage of Di2 and EPS over mechanical is just down to people not maintaining their mechanical systems properly. My shifting is just beautiful and effortless now, can't think why I would need electronic. But of course that's maybe the advantage of electronic, that it doesn't need to be maintained.
  • cougiecougie Posts: 22,512
    I dont change the inner cables either? Unless I'm swapping to a new bike or something.

    Never have a problem with shifting.
  • mugensimugensi Posts: 558
    I put new jagwire outers on my winter bike 4 years ago and have ridden it predominantly in the wet and winter time and the gears/brakes all work faultlessly and smoothly. I'll change them if they look or feel like they need changing.
  • neebneeb Posts: 4,362
    Oh well, maybe I was just unlucky and somehow acquired damaged / clogged-up cable sheaths against the odds!

    <edit> but don't underestimate the potential not to notice if your shifting isn't perfect, it's easy to assume that what you have gradually got used to is normal.
  • I finally got round to replacing mine this spring after about 5 years and 20k miles in all conditions.
    They didn't really need replacing tbh, although it has improved the rear braking and gear shifts a bit. I really just thought it would be nice to fit shiny new cables after fitting the new groupset the previous year.

    With care the cable outers can last a really long time!!
  • fat daddyfat daddy Posts: 2,632
    the only time I have ever changed mine are when upgrading the gearing or when I crashed and destroyed part of it !
  • neebneeb Posts: 4,362
    I think I must have had little gremlins in mine, all banding together for a massive tug-of-war every time I changed gear.. It's just soooo light, smooth and snappy now by comparison. I've been happy about it all week! :D:wink:
  • keef66keef66 Posts: 13,286
    Only ever replace bits that stop working properly. Usually that's the rear inner cable, fraying (or actually snapping) inside the 105 shifter. Occasionally the short loop of outer at the rear derailleur. The rest of it seems to keep working indefinitely; 9 years and counting on one bike.
  • webboowebboo Posts: 2,710
    I thought I'd better change mine after I changed gear and was suddenly covered in plastic dust as the outer disintegrated.
  • fenixfenix Posts: 5,437
    I'm treating my winter / cross bike to new brake cables after 6 years. And only because its getting hard to brake on the rear. I blame the open cable on the top tube. If the outer ran all the way I'm sure it would still be fine.
  • SecteurSecteur Posts: 1,971
    I think this is a fair point. Water and wear does get into even the best quality cable outers , and changing them (or even just squirting GT85 down the empty outers when changing the inner) can make a big difference.

    I would personally say I'd change them every 2 years or so and honestly half of the reason I change them is because I like to fettle rather than any problems shifting.

    So in addition to the benefits of shifting performance and the enjoyment of fettling, I also find new bikes tend to have very long and sloppy outers around the front end, and I like to neaten them all up by cutting to optimal length - more of a cosmetic thing, though excessively long (or short) outers will affect performance.

    Oh, and a 4th reason is simply to change colour - my first bike was black but had grey cables - I changed them to white ones (and upgraded to jag Wire) and the bike looked so much better.
  • larkimlarkim Posts: 2,299
    I think you're right to point out that small incremental degredation of any component can easily go unnoticed until you make the change to new.
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  • Calendar times are meaningless, what is important is riding time, miles ridden and type of conditions (wet, dry etc). I find in general 3,000 to 4,000 miles. The real wear takes place on the outers, especially at the bends. The first noticeable sign of degradation is usually the rear derailleur on downshifts.
  • neebneeb Posts: 4,362
    The real wear takes place on the outers, especially at the bends. The first noticeable sign of degradation is usually the rear derailleur on downshifts.
    Yes, that's what Graeme from velotech told me. The loop of outer cable that goes from the chainstay to the rear DR can get worn internally on the outer part of the bend. I suppose the cable eventually just wears a groove in the inner liner. I can't think what else it could have been in my case.

    Another thing I read was that if you remove and reinsert a used inner cable with a slightly frayed end it can damage the liners. So probably best to never reuse an inner cable.
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