Shift cable replacement at 6,200 miles?
 

2024 Domane SL5 with Shimano 7100 series 12 speed manual shift. At 6,200 miles the rear shift cable is broken. The dealer’s mechanic says that it normal for that bike at that mileage.

I’m thinking no way but maybe I’m wrong? Is it normal to get so few miles out of a shift cable?

More info. There are some hills where I ride. Most of my rides are 50 miles and the average elevation gain is about 2,000 feet.

:popcorn

6+k miles is a lot for a rear shift cable these days. At one time earlier in the indexing world Shimano recommended shift cable replacement every 1000 miles. Ever wonder why there are so many "my shift cable broke and now I can't get the head out of the lever" threads here?

Then there's that different riders are kinder or harder on their cables. Or that there's a difference in how many shifts a mile might be done dependent on terrain, so life rated by only miles could be lacking. Your 40' a mile type rides are pretty close to what my region sees and I tend to replace my shift cables every couple of years on my frequently used bikes, which is around every 3-5k miles per bike. This is about the same rate of handle bar tape wearing and chain wear so I will often do it all at the same time.

The shop I still part time at has a customer who was breaking his rear shift cables every year between his two bikes. Finally after having to replace a shift lever (thankfully when Shimano still offered the blades/shift pod sub assemblies as a se[arate item) because the cable end was too jammed to remove he asked us to just replace his cables any time his bikes were in for service. Which being about twice a year for his #1 and once a year for his touring ride was enough to keep the bikes reliable for his mega rides in VT.

I suggest replacing the cables sooner, before they break. Yes, this means spending some money/time/effort before the absolute end point. How much do you like to gamble? Andy

Thanks for that. I just wanted to make sure I wasn’t being blown off. In the future I will try a 5,000 mile preemptive replacement. Or maybe buy an SL6 with electric shifting. lol

when i was sponsoring a CX racer, he broke a shift cable riding the STP (Seattle To Portland) fun ride.. he finished the last 30 miles in #8 rear, and shuffling between the front rings .
luckily for him, Hwy 30 is fairly flat from Longview to Portland.

a sag wagon driver adjusted his high set screw in all the way to get him out of #10 rear...

guess who got to dig out the remainder of that cable (maddog raises hand.)
we decided that changing his shift cables every spring was a good plan. Dan rode a LOT back then.

you ride a lot too ;)

Shimano shifters eat cables - just make a note to replace yours every 5,000 miles or less, and grease the nipple, so you can remove it before it snaps off and gets stuck in the lever, as that can wreck the lever. Use a good quality stainless cable like Jagwire Elite, the slick polished surface has low friction that reduces stress on the shifter and helps smooth shifting.

Since your shift cable is indeed broken, it would seem that you are, in fact, wrong. :)

When you posted the popcorn, I knew I had screwed up!

So, let me add a serious note to my smart-ass reply!

I have Shimano 11sp mechanical on a bike, but the cable routing (under the bar tape) is about the same. And I have broken RD cables in as little as 1500 miles. Since cables are cheap and easy to replace (YouTube is your friend), I just always keep at least one spare inner cable on my workbench and replace at 1500 mile intervals. (I replace the housing every 2-3 times, as that seems to last longer before the shifting starts to get a little balky.)

The reason for the preventative maintenance is that, if the cable breaks inside your shifter, it can be very difficult to remove the splintered bits. If you're on a ride and your RD will not shift down the cassette (I.e., onto smaller cogs), that means your cable has broken and you want to NOT SHIFT AGAIN! Just get home without shifting. The more you shift it, the more likely that it gets really buggered up.

Hope this helps!

6k seems on the short end or reasonable, but still reasonable. My Campag Chorus 10 rear shifter tends to eat cables. The shifting starts to deteriorate and finally loose strands poke out from under the hood. I've started replacing the rear cable every year (5-6k) as a preventive measure before it gets to the strand poking stage. I can leave the housing in place and simply thread the new cable through.

Because of the internal routing and the complexity of brifters I’ve never tried to change a cable. Plus I’d need to buy the tool but that isn’t the obstacle.

Periodic shift cable replacement is just a part of the cost that we suffer with for having current indexed shifters. As bikes become more complex this type of cost is likely to become greater, and of course the parts will be getting more expensive. Andy

Replacing shift cables and housing is a normal thing and letting them linger for long periods will end up with poorer shifting or broken cables which is even worse. Good stiff housing and nice slick stainless polished cables from Jagwire are an excellent upgrade and plus it allows you to change your tape which after a lot of miles might could use some replacement being soaked with sweat.

I would for the next bike go Di2 but that is purely because the shifting is better and so easy to work on and then easy to deal with. You still want to replace bar tape with some regularity but you don't really have to adjust ever if at all once set up and at least on the older stuff you just need to charge a single battery, though replacing a couple coin cells once in a while isn't terrible.

You could always choose a bike that accents serviceability. But then you wouldn't stand a chance of winning the TdF as you likely will on your Trek.

I am curious as to where in the run did the cable break. Near the shifter, near the derailleur or somewhere in between. On my ancient Bianchi mountain bike the rear cable runs under the BB in a plastic guide and it takes a lot of abuse.

Shimano PTFE cables have consistently been the shortest-lived cables I've used. I've never gotten more than 6,000 miles out of a Shimano PTFE shift cable. Conversely, I regularly go over 9,000 miles on polished Jagwire or even polished generic cables.

They always break in the Shimano road STI shifter/brake lever about 1/4" from the cable head. They have been doing this for 35 years.

First time I wore out a rear shift cable at around 4,000 miles I think, I started replacing every 6 months which was around 2,500 miles. I could have gone longer, but it's easier to remember every 6 months (2X per year) than something else.

It's easy to do, and doesn't require any special tools.

It of course was a Shimano shifter and the cable frayed and broke in the turn into the shifter. Some disassembly required to get all the little pieces of cable out. There's simply no reason to push this. It's nearly trivial to replace. Sucks to have to limp home without being able to shift and sucks more to spend a long time cleaning frayed cable bits out of the shifter.

Unless you have a bike like the OP's where the cables are routed through the stem, headset and frame.

You either need to acquire a real skillset and specialty tools, or just pay a good shop to do an annual tune-up priced commensurately to the amount of screwing around necessary.

I'm pretty sure there is cable housing running through all that. So, why would it be hard to run a cable through that?

You are correct - I had to look up this model and it does use full length housing. Good catch.

None of the similar Specialized bikes I was building used full length housing and quite a bit of the bike had to come apart to get a wire through.

1500 miles seems excessive Koyote - what state are those in when you remove them? Surely you must have been unlucky that time one broke that soon?

I haven’t heard back from the shop yet. But on my older bike, it almost always broke inside the shifter. I do recall once when the cable frayed at the rear derailleur.

I certainly didn't know one way or the other about this bike. I just can't imagine any bike wouldn't have housing running through things like the stem or headset, if the cable routes that way. I can't see how that could possibly be done unless there was just some overly complicated feature of the stem and headset where it acts like the housing. I guess anything is possible. Though even then, it would seem you could still slide a cable through.

I am curious. If you can give me info on a bike that is complicated like this, I'd like to look into it, just to understand how bad things can be.

Thanks for the reminder. 4,700 miles on my Domane, so it's time. Ordered.

Same mechanical 11 SPD Ultegra on my Fog Cutter, and I went to 10k before replacing. Not recommended.