The Beacon Message Board

On Sunday I snapped another rear gear cable at the lever end. This one lasted just 3000 km and again broke inside the lever making it a nightmare to get out. In the end I had to detach the lever and virtually disassemble it in order to dig out the nipple which becomes lodged in the mech. Yuk. In doing so I discovered that 2 bike shops between them had failed to assemble the bike with the correct gear cable ends (using standard ends instead of the ones supplied by Shimano which have tongues on them designed to lower friction and keep out dirt) and forget to replace one of the bracket covers and hence allow more dirt to enter the lever and allow the detached nipple to float around in the mech. Disappointing to say the least.

Quite how anyone can not fit a gear cable incorrectly is beyond me to be honest, how hard can it be for goodness sake?

Don't know if you saw my post from the intro ride. On that a cable snapped in the same place on a guys bike. He had a"full " service at a bike shop shortly before. The bike shop had told him" we only replace cables when they need it"
How exactly they would know it needed replacement without removing the cable is beyond me. And if you remove the cable it is easier to replace it with a new one, particularly important with the greater complexity of gear cable direction on 10 and 11 speed systems.

I would not trust my bike to un trained kids on minimum wage. Do it yourself and change cables regularly.

Sheldon Brown has a rather good page on gear and brake cables.
Although I inevitable carry a spare cable I haven't needed on since 2005 whilst touring the Faroes and that on a bike with downtube shifters which I often left over a year before putting new ones on. A ten minute job..With STI levers I change the cable inners every spring. If I had 10 speed shifters I would be inclined to do it twice a year because of the routing of the cables.

The funny thing is I was talking to Nic about my intent to change the front mech's cable since it was 9000 km old. 20 mins later, the (3000km old) rear mech cable started getting sticky. It snapped just after the café Like all good professionals Nic did have a spare cable with him, but it would have been a 30 min road side fix even with experienced hands.
So I wound the rear stop up to max (13) and did some meaty hill climbs for the ride home

I replace all my cables, both the inner and the outer every year without fail, usually just after the winter months

I have to report that apart from yours Barry I've seen two other bikes with the same issue. One at work with 6800 Ultegra and one at a race 9000 Dura Ace both broken same place. I doubt if many bike shops will have the new shimano cables that's why they weren't used. I've not seen anything from shimano saying you have to use their cables either.
Looks like this could be an issue.

Interesting Chris. Were the gears fitted with the correct end caps?

Having disassembled my R lever, in hindsight I'm pretty sure that the issue you helped me with (lack of indexing) was caused by the cable nipple dislodging due to sticky outers and a lack of bottom plate on the lever. (In fairness I should add that said LBS immediately ordered replacement part when I notified them of missing item).

According to various websites, Ultegra groupsets come complete with inners/outers and end caps, but I cant find exact details. And there is a replacement cable set *specific* to the 6800:

http://www.chainreactioncycles.com/shim ... prod127586

which includes the important end caps with tongues. In particular, one that runs in to the lever where there is potential friction and another that inserts in to the rear derailleur adjuster barrel where, in high gears, there is a particularly sharp angle to the anchor bolt.
The barrel tongue is interesting because its not even detailed in the service manual. Maybe Shimano are picking up on reports, have added another very cheap fix, and havnt updated their manual?

The manual also states that the cable guide inside the lever should be replaced each time a new inner is fitted, but it is not included in the cable kit!

Clearly there are tight corners for the cable to travel through, but Shimano have evidently tried to mitigate these by extra slippery cables (the things are positively slimy) and judicious use of guides. If these are not fitted (like mine originally), then its no surprise that breaks occur at the weakest point of maximum wear- clearly inside the lever mech.

Anyway, mine are now fitted with new inners/outers and proper end caps (but not a new lever guide), so we shall see how long they last. Knowing my engineering skills, probably next week

I'll be sticking with my not so sticky 7800 group then still brilliant and no stupid fancy cables.

Patch wrote:I'll be sticking with my not so sticky 7800 group then still brilliant and no stupid fancy cables.

I have 6700 and 7700 shifters on my road and touring bikes, both do not have the gear cables coming out the back of the shifters, so the pull is in a straight line. I assume this must remain the case with the 7800 shifters as I assumed the more complicated cable run is what causes cable breakages.

I hope this is the case otherwise I won't ever get round to going 10 speed (I have noticed that second hand 7800 stuff is now often cheaper than 7700 and this naturally interested me) as the areo advantage of hidden cables may be worthwhile to some, but the complicated cable run is a definite no go for me.

Exactly the same happened to Trevor Richards on Sunday. It makes me wonder what is going on!

I wrote to Shimano 2 weeks a go asking why they did not include the inner-lever nylon cable guide (cost c. £0.05) in their cable replacement kit when they state in their own service manual that it should be replaced every time the inner is changed (everything else is included in the kit), but I have yet to receive a reply!
My gear cables are now silky smooth and still going strong after 200 km

I reckoned after 2 or 3 winters on my winter bike it was time I changed some cables but on checking I found I've had it for four winters. When I changed the rear inner cable (which looked fine) on Saturday I thought "at least the best bike should be ok for a bit longer" (cables changed same time but less miles since). On the best bike today, changing up to a higher gear was a bit iffy and on the last hill before home the change down didn't feel quite right. When cleaning the bike, I checked it and the cable broke. Good timing but lesson learned.

I never received a reply from Shimano!

I took my Genesis Equilibrium round to Alan Weaver's tonight to try and diagnose the issues I was having with my rear derailleur. After us scratching our heads and realising it must be a cable issue, we peeled back the rubber hood of the shifter, and found the frayed cable mangled into the 105 shifter.

After some time, we managed to fish the remains of the cable out of the shifter, but it would appear this is quite a common issue!

deero83 wrote: we peeled back the rubber hood of the shifter, and found a frayed cable mangled into the 105 shifter.

I had exactly the same issue a few weeks ago. Was a bit of a nightmare getting all the bits out of the shifter and by the time I'd finished I'd managed to pull the cable through the frame.... Spent half an hour getting the new cable through the internal routing, fishing around using a small Allen key as a hook. Felt like I was playing the game "operation"! lol

Andy and helen, what groupset do you have?

slogfester wrote:Andy, what groupset do you have?

105, and I'll admit that I have never seen a cable frayed as bad as that before.

slogfester wrote:Andy and helen, what groupset do you have?

105. I must admit the cable was 2 years old.....

Hels147 wrote:

slogfester wrote:Andy and helen, what groupset do you have?

105. I must admit the cable was 2 years old.....

Mine was probably the same age, but then I thought Venture Bikes had replaced them when it had a service a few months ago. It would appear not!

Moral to the story, replace all the inner and outer cables every twelve months. I replace mine after every winter without fail.

Another reason to go electric

How would Di2 stop a cable fraying?!

dweben wrote:Another reason to go electric

I have not progressed to cables yet, let alone electric. My braking and gear changes are driven by metal rods.

deero83 wrote:How would Di2 stop a cable fraying?!

This thread is about gear cables Andy, di2 is electronic shifting so no gear cables to fray.

deero83 wrote:

Hels147 wrote:

slogfester wrote:Andy and helen, what groupset do you have?

105. I must admit the cable was 2 years old.....

Mine was probably the same age, but then I thought Venture Bikes had replaced them when it had a service a few months ago. It would appear not!

Is that 'thought' based on what it was agreed at the time the service covered? (I've run the same gear change cables for many years on bikes without changing them - without cable failure - so, on the basis that it's something i've then got to pay for, wouldn't necessarily want them changed by default...)

Like John, I've run cables for many years without a problem. In my opinion, if a gear cable is well made and well fitted, it should never fail in normal use.

I don't use Shimano myself, so my experience lacks specific relevance. However, the only gear cable failures I've experienced have been down to errors I have made setting up/maintaining the bike, particularly:
- Repositioning a lever after fitting the cable (e.g. because the lever has been knocked off square by a fall and then straightened), leading to friction and fraying at the point where the outer cable meets the lever
- Snagging an inner cable when threading it through in-situ outers

Given that inner cables cost peanuts, and outer cables and bar tape only modest amounts, my policy is nowadays:
a) Leave well alone
If everything is working, why undo your cables? You can clean and lubricate the bike perfectly well without.
b) Every couple of years, take off inners, outers and bar tape, bin the lot and fit new.

George wrote: In my opinion, if a gear cable is well made and well fitted, it should never fail in normal use.

It all depends on your interpretation of "fail" really? As mentioned many times before I replace my cables every year and the only reason is to maintain the performance of the gear changes and also the hopefully reduce any possible risk of cable failure when you least expect it.

In my experience cables suffer from water ingress and capillary action only serves to draw more water further along the cable inner/outer. This is certainly the case with the short section of outer cable adjacent to the rear mech where both ends of the cable are open to spray from the wheels. That said and to be fair to Shimano they have tried to address these with the newer group sets, by including plastic cable end sleeves that have a 20mm tail on them to reduce this from happening.

Furthermore, I have also noticed that the inner cables tend to ever so slightly swell over time and subsequently cause slightly more friction against the outer casing.

Certainly with 11 speed drive trains, the tolerances are much tighter so the need for pre planned maintenance is important if you want to maintain that crisp effortless feel and operation.

Or maybe its just my OCD.....

martin mc wrote:

deero83 wrote:How would Di2 stop a cable fraying?!

This thread is about gear cables Andy, di2 is electronic shifting so no gear cables to fray.

Ah - I hadn't thought about the fact that it was an electronic wire not a traditional cable. My mistake.

AlanW wrote:It all depends on your interpretation of "fail" really? As mentioned many times before I replace my cables every year and the only reason is to maintain the performance of the gear changes and also the hopefully reduce any possible risk of cable failure when you least expect it.

Alan, by 'fail', I meant break (or start breaking). I didn't say that it wasn't a good idea to replace cables for performance reasons. Given the difference between your annual mileage and mine, I think that we are probably replacing cables at similar service intervals. And for similar reasons: gunk and corrosion and kinks marginally reduce the cleanness of the pull and the positivity of your gear shift.

But the point is that a tarnished, gunky, kinked cable shouldn't actually break for years and years. The question posed at the start was (I paraphrase) 'why do my cables keep breaking'. And the essence of my response is that they really shouldn't be breaking in normal use, even if you've left them on the bike for a long time. Therefore, if they are breaking, something fundamental must be wrong. Either the cable's faulty, or the installation's faulty, or something's changed since installation to make the set-up faulty.

I think you have answered the question George , in that cables breaking is down to poor instillation.
Since my original post about a rider on an intro ride having a cable breaking (following a "full service" at a bike shop ) I have witnessed a further breakage on a club run ( a bike never serviced since purchase from a boutique style cycle shop.
I initially put this down to the more complicated cable run of under bar gear cables. However since then I laid my hands on some second hand 10 speed Ultegra under bar style levers and can see nothing that could cause these breakage that is intrinsic to the design.
Out of habit I usually carry a spare gear cable and change all cables used over winter in spring. It may be overkill but takes a few minutes and costs next to nothing.and I have never had a problem.
I have never used over priced "Shimano" branded cable by the way.