Rear shifter cable fail

cmhill79

Hi Folks

How often are you changing your rear shifter cable? I seem to be getting issues every 6 months (roughly 3,000 miles)

The trouble is they go without notice and leave you very restricted in terms of gears. Fortunately I have not been far from home each time but I fear one day my luck will run out!

luv2ride

I'd also be interested in the replies you get. I've got a few bikes, all with various SRAM road gruppos (apex, Rival, force). None have had any issues with the cables apart my newest, which had a rear inner gear cable fail after no more than 10 rides. It snapped at the retaining nut on the rear derarilleur. General consensus was that it may have been over tensioned by the LBS who built it up for me.

I replaced it yesterday so will see how it goes, but don't fancy struggling home in 'top' again like last weekend Have also bought a few spare cables as well though just in case...

ElectronShepherd

@cmhill79 - it depends where it's failing. If the cable is breaking at the clamp, there may be some sharp edges on either the clamp or the derailleur body, cutting through the cable.

@Luv2ride - if it happens again, you can sometimes wedge a small twig into the parallelogram to keep a lower gear to get you home. I don't see how "overtensioning" (presumably you mean doing up the clamp nut too tight) would cause the cable to break. It sounds to me like there's another problem there - hopefully it was just a one-off duff cable, but maybe the sharp edges mentioned above.

solosuperia

I find it unbelievable that you are having cable failure at such a short interval!
It has been my argument against electronic gears that the cables are almost infallible...........
Mine seem to go on for years/miles with the minimum amount of maintenance.
Must be the cable run or suchlike, the area that goes might give you a clue.

Monty Dog

I have gear cables approaching 10 years - suspect there's a burr on the underside of the clamp-plate that's slicing your cable.

hostman

I recently had a rear shifter cable fail 5 miles from home, thankfully it was relatively downhill at that stage.

This is on a bike 18 months old, 1600 miles or so.

I may start changing the cables after 1400 miles or so in future. But of course it's not just the cables, you really need to do bar tape again also, which is a bit of a pain.

Initialised

I had one snap at the shifter end, the end piece fell inside the housing and was very hard to dig out.

I had to take a flat route home as I only had 34 x 11 or 50 x 11 available.

Apparently is was due to corrosion after winter riding.

Under a year old, around 6000 miles use.

Now I give the shifters a squirt of GT85 everytime I clean the bike.

alan_sherman

Does no one know what the adjustment screws do these days? Wind it in a bit to get two usable gears

briantrumpet

I've had three rear shifter cables go, all in the brake shifter housing, where it turns a bit of a corner to enter the handlebar cable housing. Several thousand miles on each one - each one has started to seize up as the frayed cable caught in the housing. Worst comes to the worst, you can just tie off the cable somewhere on the frame to get your two usable gears - fortunately when this happened on a ride out into the Alps, it broke before I hit the big mountains, and had just a 25-mile ride home on flat roads. I suppose that if had had had a long climb to do I'd have just tied it up tighter for the climb.

Incidentally, the shifters are 105 and Ultegra on the respective bikes, so perhaps there's a generic design problem there.

luv2ride

Good points, will check my RD cable clamp for burrs or any sharps edges. As you say, the shifting should get noticeably worse (I.e. requiring replacement) before the cable snaps or shears.

Initialised

Luv2ride wrote:

Good points, will check my RD cable clamp for burrs or any sharps edges. As you say, the shifting should get noticeably worse (I.e. requiring replacement) before the cable snaps or shears.

That wasn't my experience, it simply went from working to not working all of a sudden, there was no drop in performance first.

dennisn

SoloSuperia wrote:

I find it unbelievable that you are having cable failure at such a short interval!
It has been my argument against electronic gears that the cables are almost infallible...........
Mine seem to go on for years/miles with the minimum amount of maintenance.
Must be the cable run or suchlike, the area that goes might give you a clue.

As above. Mine never fail. I would guess that as the cable moves it's rubbing metal to metal at some point on the bike. Does it break in the same place each time?

cmhill79

I'm generally having issues with the cable inside the shifter. These issues have been over two bikes with Tiagra and Dura Ace so it's not restricted to lower or higher end components.

rolf_f

ElectronShepherd wrote:

@Luv2ride - if it happens again, you can sometimes wedge a small twig into the parallelogram to keep a lower gear to get you home.

Or you could just carry a short length of gear cable with you to do the job properly - allowing you to select any gear you like as appropriate.

alan sherman wrote:

Does no one know what the adjustment screws do these days? Wind it in a bit to get two usable gears

Might only get you one extra and if the terrain is hilly it might not help much (though obviously every bit helps a little!)

dennisn

cmhill79 wrote:

I'm generally having issues with the cable inside the shifter. These issues have been over two bikes with Tiagra and Dura Ace so it's not restricted to lower or higher end components.

Are you the one doing the work? Not that it matters, because I'm of the opinion that it is installer error. Someone is not installing the cable correctly. At least that's my best guess. :?

MountainMonster

I guess I've been lucky in never having cables fail on me.

dennisn

MountainMonster wrote:

I guess I've been lucky in never having cables fail on me.

Maybe not so lucky, but you, or your cable guy, are / is doing the the job correctly.

MountainMonster

dennisn wrote:

MountainMonster wrote:

I guess I've been lucky in never having cables fail on me.

Maybe not so lucky, but you, or your cable guy, are / is doing the the job correctly.

Yay, I do good work! I'll have to remember that.

Virtual pat on the back.

desweller

I have had raised edges on new shifters in the past causing this problem.

A quick op with an appropriately selected drill and some grease on the cables sorts it out.

keef66

My 105 has twice eaten the cable inside the RH shifter; the second time I ignored the crunchy gear change till it snapped completely, but luckily I was still able to retrieve all the bits. So mine are lasting about 2 years, which is a bit better than your experience, but still pants. I had MTB shift cables last 10 years.

patrickf

alan sherman wrote:

Does no one know what the adjustment screws do these days? Wind it in a bit to get two usable gears

Exactly what I'm thinking. If your cable fails, simply adjust the high limit screw to get you into a more manageable/useful gear.