Replacing Gear Shift Cables on 105 (5800) Groupset

As the title suggests, I am looking for guidance from the mechanics out there to replace the gear shift cables and housing on my CX/Gravel Bike. To be honest, I maintain this bike VERY well and I do not have any problems with shifting. It’s just that I’ve had the bike since I bought it new and it’s seen a lot of gravel/dirt and mud over this time. I’ll be taking it into the shop for a complete rebuild including new bar tape (hence thinking if I am gonna replace the cables, I should do it before I wrap the bars).

The bike is a 2017 Focus Mares AL 105 with shimano hydraulic disc brakes.

Front and short-cage Rear Derailleur are Shimano 105 5800 series.

I am a little confused about what cables to get.
I am looking at these:

or this

the differences are subtle, but I don’t want to end up buying one and not being able to use it, or take advantage of the upgraded tech that appears to come with the OT-RS900 on my 5800 series

FWIW, all of the available ones are here:

Thanks in advance folks :slight_smile:

The only difference I see is one comes with a short chunk of cable housing specifically for the rear derailleur and the other doesn’t. Both look like they’ll do the job. I can’t comment much on Shimano shift cables as all mine have jagwire cables in them because I can get them cheaper from my local shop.

The only helpful advice I can offer is pay close attention to how the cables route thru the derailleurs and into the pinch bolts as getting that routing wrong can sometimes cause shifting issues.


This is just my experience, although I’ve seen it echoed by others, probably not all. I avoid all Shimano Whatever-Slick TM coated cables. The coatings start smooth but get shredded.

Jagwire and Alligator, and I think also Shimano, make stainless cables where the outside braids are machined down to a smooth cylinder, and then polished. They are smooth and they last.

Jagwire claims their lighter weight housings are just as stiff, and Alligator claims their higher strand count cables will last longer, which should in principle be true, and they are clearly more flexible. I’ve used both with no problems but haven’t paid enough attention to verify either claim.

You want that bit for the rear derailleur. You can buy them separately though. As Sir_Alan stated, issues near the derailleur matter, and the wrong housing there impacts flex in ways that might matter. If the 5800 uses standard housing for that, then it doesn’t matter. Some use a thinner piece though with a shimano part number.


The first one comes with the OT-RS900 which is a slightly thinner, more flexible cable that runs the last section from the chain stay to the rear derailleur. I believe the more recent Shimano groups sets (r7000 onwards) advise this as it helps shifting. As it’s for a CX/gravel bike I would think the subtle improvement would be soon lost in the mud! Looking to use sealed end caps might be more worthwhile for your application.


I’ve used Jagwire for cables and brake pads! Great company and they make some interesting combinations


Shimano Optislick cables are not at all like previous Shimano coated cables where the coating sloughs off and gums up the works. The old Gore cable sets were also notorious for this. The Optislick coating is hard and has a slightly greenish appearance. Optislick cables with Shimano SP41 housing works very well and is what I’m currently using. Jagwire polished cables work well too. Starting with good cables and housing is half the battle. The other half is doing a good installation.


Don’t forget to remember to inspect and, if needed, lubricate. Grit and dirt are these cable types biggest enemy.

I’ve run jagwires for years with no issues. Recently put in new ones as was also doing a full strip and rebuild on the Scott and the old jagwire cables were still absolutely perfect. I have always eventually had fraying issues with Shimano, though I know the newer ones are meant to be better.


FYI, and just to be clearer, I’ll be getting my LBS to replace the cables when they do the rebuild. There’s a bunch of tools I don’t own nor want to own.

My main concern is whether the gear shift cable set with the OT RS-900 would work on my bike as it says it’s designed for the R7000 series while I’ve got the 5800 in the bike.

Thanks to all who have responded so far. Also, cuz I took so long to make a decision, the deal I was looking at is now gone :man_facepalming:t3:

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R7000 is an Optislick set so will work very well with any Shimano gruppo. The OT RS-900 is a short flexible housing used to make a tight bend at the RD if needed. It is not truly compressionless because it is spiral wound. However, since it’s short, it doesn’t present a problem. That said, for most setups with the usual RD loop, I’d stick with SP41.


Thanks. I think that’s the info I was seeking.

Every cable will fray and break eventually. I’ve chewed up many of Jagwire’s “Pro” cables, although it does depend on the shifter model. For me, all brands will break before 5000km (rear shifter of course), sometimes much before, but I ride lots of hills and shift a lot, and probably abuse shifts sometimes, pre-shifting too many gears sometimes without pedaling enough maybe, not sure, trying to pay more attention to that.


Ah… it does seem by all accounts that this is probably true. The ones I had were I think billed as ultegra and dura ace level, and shipped on such bikes, but it seems there was a time, not long ago (or maybe still?) when they were pushing the soft-coated junk on with their top equipment, so you’re probably right. Maybe that mess is even still the best for pro racers with a mechanic changing cables before every stage. I switched to stainless only have seen no need to look back. They operate flawlessly, but optislick may also.

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That they do. I typically get about 10,000km out of a set of shifter cables. Pretty hilly here too and I’m known to multi shift a lot, but am pretty good at avoiding shifting under heavy torque which probably helps.


agreed, if it the derailleur came with RS-900 it needs it to avoid stress there, if not I don’t know if RS-900 would still be ok, but with how sensitive derailleurs can be, I’d still with original equipment, which in many cases is standard housing. RS-900 might not even be the correct length in all cases (I can’t recall if it’s provided in excess lenght). I think the ones that use that have the barrel adjuster pointed upward (mine does), and possibly a shorter loop.

Of course buying a set with the RS-900 shouldn’t hurt so long as there’s enough excess housing to cut a loop from standard housing anyway, and surely there likely is. If a shop is installing it, they should know what to do I’d hope.

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There was a good deal on what would’ve been the “stock” variety but I dithered and lost.

We’re only talking a few bucks though.

No biggy, but thanks all for the help. Next time I’ll ask sooner.

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Another +1 for Jagwire cables & housing. I’m using them on my Rival 1 system. Super easy to replace and they come in fancy colours!


If you are breaking cables, something is seriously wrong. If you are wearing through them that fast (I’m assuming less than a year), you need to regularly inspect and lube those cables. The coating does NOT eliminate the need for routine maintenance. Not by a long shot. If you are getting your cables wet (and I mean immersed, not just rain falling on them) you may need to use a water-resistant grease, not just oil, to keep water penetration at bay. I speak from years of riding experience and I only replaced cables when the ends were frayed or individual strands were starting to separate. Cables routinely lasted me several years.

Some years ago there was a common problem with Shimano shifters where the cable would fray and get stuck or break in the shifter, almost always the right one. It could be quite difficult getting the frayed or broken cable and head out of the shifter. There were a few times we (I was a mechanic in bike shop) had to drill a hole in the side of the shifter to get it out. The hole was under the hood so no issue doing that. I never figured out why that occurred and it was only with that series of Shimano shifters that I’ve seen it.

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I would say this is STILL a “problem”… And one you want to avoid at all costs. It happens much sooner on the rear shifter than the front, generally, which is logical because of the difference in how often they are used. I’ve run the front cable well over double the miles as the rear cable, and still haven’t seen the fraying issue, which is usually visible if you look closely into where the cable begins in the shifter. Pull back the hood cover and shift through the gears, inspecting all that is visible of the cable, and you may see it beginning to happen, individual wires already breaking.

I BARELY escaped the nasty situation Saddlesaur mentioned, when my rear cable broke inside the shifters. I had already ignored the EARLY WARNING that this is happening: the rear derailleur stops shifting cleanly and needs some adjustment at the barrel adjuster, and this is to get MORE tension on the cable. That’s because with many individual wires on the cable already broken inside your shifter mech, the cable really DOES STRETCH. So you have to use the barrel adjuster to dial it in again, and that’s when you BETTER CHANGE CABLES NOW!
I didn’t heed my own advice… I thought I’d tweaked a derailleur out of true somehow, and missed the warning signal!

I was fortunate that with some time-consuming and careful work I was able to get the frayed wire back out of the shifter without having to resort to a lot of digging bits of broken wires out too. That can cost you a small bundle of cash if the shop has to do that for you because you let the cable break. I do almost ALL bike maintenance myself on my bikes because I can and because it’s a hassle to drive an hour away and leave my bike and return another day, but my shop advises changing the cables by 2500 miles to avoid that very issue. (I always get much more than that before changing, but I’d pushed it too far this time when mine broke, close to 4500 miles.) And on this particular occasion, I had just recently done an inspection inside the shifter trying to see if there was any fraying, and I saw none and thought I was okay. However, the fraying happened about 3/4" up from the endpoint of the cable and I could NOT see it happening.

My best advice is PAY ATTENTION TO EARLY WARNINGS! When either derailleur seems to get out of adjustment, it MAY be because the cable is already fraying somewhere.
I use standard Shimano stainless steel cables. They are quality made, can often be found in bulk at very reasonable price, and slide will inside housings. And it is SO EASY to change a cable before it breaks. Yes, a little fiddling to dial everything in but pretty minor, really.

One other thought, aimed at bike manufacturers, PLEASE DESIGN BIKES FOR FULL CABLE HOUSINGS, especially if cables are INTERNAL! I’m not a big fan of internal with PARTIAL HOUSINGS, but with FULL HOUSINGS, it is a GREAT IMPROVEMENT. Almost nowhere for corrosive elements to intrude, cables are protected from wear and make cleaning the exterior of the bike so much easier, and yeah, the aerodynamics of the bike are improved too.

When I made the first cable change on my DOMANE, I was braced for some fun, expecting to have to fiddle with routing the cable through the frame and all that potentially entails. I looked inside the handy storage area in the downtube, accessed by removing the little door that holds the water bottle cage, and realized the cable housings (and disc brake hose) were complete all the way through the bike! HAH! A simple process of cleanly cutting the cable free at the derailleur and then pull it back up out at the shifter, and then push the new cable in! It was absolute joy!
I’m still running the original housings, with nearly 23,000 miles on the bike. It will take a little bit of fiddling when I have to change them out, but they are still smooth. I’m on the about the 6th rear cable, and the changes have been so easy! I can handle the fiddling required, knowing it’ll give me another 4 years of easy cable changes once it’s done.