Gear cable fraying inside Shimano shifter

[mpemburn]

A little while back, the rear shifting on my bike started to get a little wonky. It uses a Shimano 6800 brake/shifter, that marvel of engineering—and total pain in the butt to work on. When I pushed back the hood, I was dismayed to find that the cable had nearly frayed through. I'd apparently caught it in the nick of time. If the cable had broken inside the shifter, I gather that it would be a nightmare to fix.

I really don't want things to get to this state again. Is there some underlying cause for this that can be addressed? Or should I just make a point of checking and lubing on a regular basis?

 

[Sea of vapours]

The underlying cause is the shifter design and I've never seen anyone suggest that there is anything you can do beyond regular inspection and replacement. The additional trouble is that it's not invariably easy to see the fraying, so even just inspection is no actual guarantee. I've had them last less than a year / 10,000km.

Having said all that, it's not really a nightmare to extract the frayed cable once you know that there is a small cover on the bottom of the shifter body which can be removed (one bolt, accessed from below) and allows all the bits to drop out. There's a thread on here somewhere, with pictures and a link to a video on how to do this.

Clearly, it's nonetheless a somewhat annoying 'design feature' :-\

 

[mpemburn]

Having said all that, it's not really a nightmare to extract the frayed cable once you know that there is a small cover on the bottom of the shifter body which can be removed (one bolt, accessed from below) and allows all the bits to drop out. There's a thread on here somewhere, with pictures and a link to a video on how to do this.

Wow! Excellent to learn this—thanks!

 

[Sea of vapours]

Here's a video showing the cover I'm referring to being removed at about the minute mark. If you remove that single bolt then the two panels on the bottom come off and all the frayed cable bits fall out easily. At least, mine always have. Do take note of how the covers are orientated before removing them. There's no tension anywhere, they're just covers, so it's not difficult to either remove or replace them.

View: https://www.youtube.com/watch?v=KixRbKrucZU

 

[cyberknight]

Agree with the above the new design is a pita,you need to keep an eye on it as ui had one go about 10 miles from home gumming up the shifter

 

[iluvmybike]

This is very common with the 11spd shifters - the cable bends are quite tight around the ratchet so over time they start to give. It is recommended to change the cable every 12 months assuming the bike is regularly used. Avoids a drastic failure and issues with the remnants getting stuck inside the works!

 

[Ming the Merciless]

I went to bar end shifters after one too many STI levers innards breaking. Not a single broken cable or shifting problem since. Admittedly bar end or even down tube shifters aren’t to everyone’s taste. I like them.

 

[Bike Tyson]

I bought those Shimano SIL-TEC coated stainless steel precision ground round inner wire to see if they lasted longer , both went after about 4 weeks use in the same right hand shifter, back to the normal gear cables

 

[Landsurfer]

I rode LEJOG in 2018 with a single front chainring and a bar end shifter ... great ride ... When we arrived at JOG campsite I carefully removed the bar end shifter...
AND FLUNG IT INTO THE FECING SEA !!!!!
Never again ...

 

[andrew_s]

Fraying cables is pretty much inevitable.
All cables will fatigue and fail when run over a pulley, and the smaller the pulley relative to the cable diameter, the quicker they fail. The pulley (i.e. the bit of the shifter that the cable wraps round) should be 20-30 times the cable diameter for a good service life, and bike gear shifters aren't big enough for that.
Down tube and bar end shifters do better not because they are any better in this respect, but because, not being so readily to hand, they aren't used as much in terms of gear changes per mile.

 

[mpemburn]

In my early cycling days, suicide—erm, down tube—shifters were the norm. Never again. I’ve also used bar-ends and never liked them.

As fraught as some aspects of STI shifters can be, I’ll stick with them. Though, if I win the lottery, I may give the new-fangled electronic setups a try…

 

[Tenacious Sloth]

It seems to be the price we have to pay for having gear cables that run under the bar tape.

Previously, the cables used to stick out of the inside of the shifters at right angles, which resulted in a much smoother journey for the cable, resulting in much fewer failures.

Personally, I much prefer the cables running under the bar tape so am willing to change the cables more regularly.

 

[Bike Tyson]

It seems to be the price we have to pay for having gear cables that run under the bar tape.

I am running Tiagra 4600 shifters with the washing lines and they are worse for fraying cables than the Ultegra with the hidden cables they replaced.

 

[Tenacious Sloth]

I am running Tiagra 4600 shifters with the washing lines and they are worse for fraying cables than the Ultegra with the hidden cables they replaced.

Really? I must admit, that does surprise me.

I’ve always assumed that the greater change in direction over a small radius in 5800 onwards is what causes the fraying?

 

[Bike Tyson]

Really? I must admit, that does surprise me.

I’ve always assumed that the greater change in direction over a small radius in 5800 onwards is what causes the fraying?

Surprised me also, thought the same as yourself, never had a problem with 8 speed shifters, can hardly remember changing a cable in thousands of miles, I think the cables outlasted the bike even.