Gear cables breaking

neeb

It seems that every few months the rear derailleur gear cable on one of my bikes snaps inside the shifter.. I run Campagnolo but I hear it's a problem sometimes with Shimano too. I seem to suffer this more than most, however!

It's always in the same place, just above the stop at the far end, where the cable runs through the shifter body. I can only assume that there's some mild friction at that point that gradually rubs away over thousands of shifts (I am a fairly frequent shifter).

I can now recognise when it's about to happen, which sometimes saves a ride home in the 36/11.. The shifting goes to pot as the cable is about to break and can only be fixed very temporarily by tightening teh barrel adjuster.

I've had it happen on different bikes with different shifters (both 11sp Record admittedly), so it's not a single faulty unit.

Here's the latest one - an extremely expensive Campy "ultimate smoothness" cable, no less..

Any tips as to why this is happening and how to avoid it..?

bondurant

Where exactly in the shifter is it happening neeb? Immediate thoughts would be not inserting the outer all the way in, a manufacturing imperfection that abraids the cable, or a burr where the outer has been cut, though in the latter case I always use the manufacturer-cut end in the shifter.

brundonbianchi

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

neeb

I'm pretty sure it's happening in front of the entry point into the outer though - at or just below the point the cable enters the little groove in the top of the shifter body.

pblakeney

neeb said:

Apart from anything else, that looks corroded which can't be right. Especially after only a couple of months.

neeb

It's more than a couple of months (every few months it seems one of my bikes goes, but it's probably a year or more before any individual one goes).

I did wonder if corrosion from sweat from indoor training in the winter was an issue, but it's difficult to see how sweat could get to that particular location. Not sure it's corroded in this case, I think it might just be the "ultimate smoothness" coating.

[[edit - the abrasions on the cable stop at the end are from me digging it out of the shifter with needle-nose pliers etc.. another joy of the whole process...]]

whyamihere

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

This is total nonsense. Having enough internal friction in the cables to snap one is a silly idea, and the shifting would be unusable a long time before that.

There has to be something inside the shifter which is rubbing, and causing the cable to become frayed. Though I've not tried it, I've read many posts on various forums from people praising the ability to strip and rebuild Campagnolo levers with good spares availability, it might be possible to take it apart and see what's going on.

First.Aspect

whyamihere said:

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

This is total nonsense. Having enough internal friction in the cables to snap one is a silly idea, and the shifting would be unusable a long time before that.

There has to be something inside the shifter which is rubbing, and causing the cable to become frayed. Though I've not tried it, I've read many posts on various forums from people praising the ability to strip and rebuild Campagnolo levers with good spares availability, it might be possible to take it apart and see what's going on.

The clue would be in how far along the cable they are snapping, would it not?

Might be self perpetuating at this stage. I know I have to inflict some violence on my Shimano ones when they go like this, to get the stubs out.

imposter2.0

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

As already pointed out, this is just a rambling load of garbage. There is no particular need to change both at the same time in any case.

bondurant

I couldn't see the picture before for some reason.

So that is before the outer touches the cable ergo it is a design fault or you have something in both bikes that abraids the inner.

I have never heard of this as a common Campag issue and equally you would have to be really unlucky to have the same thing happen to more than one bike.

So I'm stumped. Do both shifters have the little plastic cable feed present? That can sometimes fall out.

pblakeney

Probably stating the obvious but....
When installing a new cable ensure that it slides freely and smoothly through the system before attaching the other end.

neeb

bondurant said:

So I'm stumped. Do both shifters have the little plastic cable feed present? That can sometimes fall out.

Yup, they're there, and the cable seems to run smoothly when first installed. I can only assume that the cable is rubbing on the edge of that little plastic thing or something like that. I DO shift a lot..

alwaystimetotorque

I've had this same issue on one occasion with a Record right (rear gear) shifter. There was nothing obvious on the outer or the nylon guide on the shifter. In the end I put it down to the inner cable catching on the gear outer steel reinforcement due to the outer not being pushed into the shifter body fully.

It probably goes without saying to ensure there are no burrs on the gear outer; make sure these are nipped off and/or filed down. The other obvious one is making sure that the outers don't pull out of the shifter when taping to the bars or when wrapping the bars.

It's certainly not a common issue that I'm aware of so long as the outer is fitted correctly. I run a number of bikes all with Campagnolo which I build and maintain myself. The only issue I have had is on the only bike I didn't build myself. Good old Canyon.

thistle_

When one of my shifter cables breaks it's usually at the shifter end.
I've always put it down to the cable being bent around a tight radius as it gets to the lever.

N0bodyOfTheGoat

Shimano BR-RS505s tend do do this from the white plastic cable guide by the hoods being frayed over time, which in turn leaves a jagged edge to fray the cable. Happened on my Cube towards the end of last summer after ~2.5 years.

There's a thread about it somewhere in the "workshop" forum section.

hdow

Probably my post from a couple of months ago about cables breaking inside a Shimano rear shifter. In front of me now sit two snapped cable ends very similar to the ones posted. Following the advice received I replaced the plastic cable guide and so far no repeat. I also check the cable every few rides, which is quite simple, and as yet no signs of fraying.
Aside 1; the front shifter itself later failed (jammed solid) and its last action coincided with snapping the cable. The shifter was replaced under warranty.
Aside 2; having snapped the rear cables then sag inside the frame and rub on the axle of the bottom bracket. There were several regular cable failures. This rubbing caused the axle to weaken and in due course snap mid-ride. This was also replaced under warranty.

webboo

I decided to change the cables on my bike today a Dura Ace 9100 only to find I couldn’t get the rear cable out due to fraying. Took in to my mates shop and he managed to get it out by taking off a plate under the lever, which I wasn’t aware of despite watching several videos on how to get the cable out. They said they had 3 other bikes in this week with the latest Shimano group sets with frayed or broken cables.

brundonbianchi

whyamihere said:

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

This is total nonsense. Having enough internal friction in the cables to snap one is a silly idea, and the shifting would be unusable a long time before that.

There has to be something inside the shifter which is rubbing, and causing the cable to become frayed. Though I've not tried it, I've read many posts on various forums from people praising the ability to strip and rebuild Campagnolo levers with good spares availability, it might be possible to take it apart and see what's going on.

I’m basing what I say on experience, something your post is clearly lacking.

brundonbianchi

webboo said:

I decided to change the cables on my bike today a Dura Ace 9100 only to find I couldn’t get the rear cable out due to fraying. Took in to my mates shop and he managed to get it out by taking off a plate under the lever, which I wasn’t aware of despite watching several videos on how to get the cable out. They said they had 3 other bikes in this week with the latest Shimano group sets with frayed or broken cables.

I’ve only had the problem of increasing seizing on Shimano Brifters, when I don’t change the inners and outers together. The last time it happened I had to pull the snapped end out with a pair of needle nosed pliers, through the slits, on a 5600 105 brifter. A bit of brute force and wiggling got it out.

brundonbianchi

pblakeney said:

Probably stating the obvious but....
When installing a new cable ensure that it slides freely and smoothly through the system before attaching the other end.

Absolutely right. It’s called ‘flossing’ cos it’s like flossing your teeth. If it isn’t moving freely, don’t fix it down.

brundonbianchi

imposter2.0 said:

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

As already pointed out, this is just a rambling load of garbage. There is no particular need to change both at the same time in any case.

This post shows Both complete mechanical ineptitude, and total lack of experience. There’s a surprise.

brundonbianchi

First.Aspect said:

whyamihere said:

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

This is total nonsense. Having enough internal friction in the cables to snap one is a silly idea, and the shifting would be unusable a long time before that.

There has to be something inside the shifter which is rubbing, and causing the cable to become frayed. Though I've not tried it, I've read many posts on various forums from people praising the ability to strip and rebuild Campagnolo levers with good spares availability, it might be possible to take it apart and see what's going on.

The clue would be in how far along the cable they are snapping, would it not?

Might be self perpetuating at this stage. I know I have to inflict some violence on my Shimano ones when they go like this, to get the stubs out.

True, it takes a lot of wiggling and wrenching to get them out usually.

webboo

brundonbianchi said:

webboo said:

I decided to change the cables on my bike today a Dura Ace 9100 only to find I couldn’t get the rear cable out due to fraying. Took in to my mates shop and he managed to get it out by taking off a plate under the lever, which I wasn’t aware of despite watching several videos on how to get the cable out. They said they had 3 other bikes in this week with the latest Shimano group sets with frayed or broken cables.

I’ve only had the problem of increasing seizing on Shimano Brifters, when I don’t change the inners and outers together. The last time it happened I had to pull the snapped end out with a pair of needle nosed pliers, through the slits, on a 5600 105 brifter. A bit of brute force and wiggling got it out.

Clearly it’s nothing to do with not changing the inner and outer in my case as I’d changed neither. Also I never have the problem of a frayed or snapped cable at the shifter in 25 years of using handlebar shifters.

imposter2.0

brundonbianchi said:

imposter2.0 said:

brundonbianchi said:

That’s a pretty typical problem that happens when the outer and inner aren’t changed at the same time. A new inner will not run as freely with an old outer, because of the internal wear of the inner, this causes excess friction, and stresses, and then the inner fails at the point of most strain ( the Internal track of the brifter )

As already pointed out, this is just a rambling load of garbage. There is no particular need to change both at the same time in any case.

This post shows Both complete mechanical ineptitude, and total lack of experience. There’s a surprise.

Come on Nick - you've got to stop claiming that your 'experience' beats everyone else's sound practical knowledge - it didn't work when you were called 'milemuncher' - and 11 usernames later it still comes across as paranoid delusion or worse. Do yourself - and all of us - a favour and log out. And then stay logged out.

brundonbianchi

Of course, all this becomes irrelevant if you use electronic shift group sets. That’s the way I’ve solved it.

stn5

webboo said:

I decided to change the cables on my bike today a Dura Ace 9100 only to find I couldn’t get the rear cable out due to fraying. Took in to my mates shop and he managed to get it out by taking off a plate under the lever, which I wasn’t aware of despite watching several videos on how to get the cable out. They said they had 3 other bikes in this week with the latest Shimano group sets with frayed or broken cables.

I do this every time with my 5800 and 6800. Saves so much time. I had one snap 4+ years back when I barely knew anything about maintenance and it took two bike shops to sort it. The next time I discovered the plastic plate and decided to have a go. First port of call every time it snaps now (which is a few times a year!).