We know, there’s no such thing as a stupid question. But there are definitely some questions too embarrassing to ask your local shop or riding buddies. Ask A Stupid Question is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question!
If your bike has a derailleur (or mechanical brakes), then you probably have a bike that is equipped with the standard cable and housing. I say probably, because electronic and hydraulic systems have replaced the simple steel inner cable in many cases, but are still the exception rather than the rule. Because the cable and housing system is so ubiquitous, it’s also a common source of questions. An often overlooked wear item on many bikes, the diminutive cable and housing can have a big impact on shifting or braking performance.
That’s why our AASQ series this week focuses on all things cable and housing. Starting with a simple question about whether you should replace the system as a whole or if you can replace one of the components at a time, we reached out to Jagwire for some input. Why Jagwire? As long as I can remember, they’ve been a fixture in every shop I’ve worked in for the cable and housing department. Chances are pretty high that if you go into a bike shop to have bulk housing installed, it will probably come from a Jagwire box (or sometimes it’s Jagwire housing in another brand’s box). And while they’ve become the go-to source for many shops for their affordable replacement parts, they also have an entire line of high end cable and housing which seemed to make them a great source for additional insight.
When it comes to replacing cable and housing – Which is more important to replace, the cable or the housing? Or should they always be replaced together?
Jagwire: We always recommend replacing them together, as this is the only way to ensure your brake and shifting systems can work at their best. Inner cables and housing wear in different ways, and depending on which type of each you have, along with the associated small parts being used, either one could wear down first.
Inner cables are typically either stainless or galvanized steel (with a zinc coating applied) to reduce corrosion. With galvanized cables, corrosion will occur once the coating deteriorates, leading to higher friction or even complete failure under load, in severe cases. Stainless steel cables are much more durable, but even they aren’t completely corrosion resistant. In extreme conditions, even stainless cables can oxidize and suffer reduced performance.
Some high-performance cables use a PTFE or other polymer coating to fill in imperfections and reduce surface friction. While these coatings can improve initial performance, they lose effectiveness when the coating wears or flakes off. In the worst cases, the flaked-off coating can actually clog the housing liner and add significant friction to the system. While uncoated stainless steel cables are typically the most durable option, even they will see reduced performance when dust, dirt, and other particles find their way into the grooves between the individual wire strands.
Housing most commonly needs replacement when the lubrication in the liner has washed or otherwise worn away, or if contaminants have worked their way inside. Either of these is difficult to see, but will affect the movement of the cable within the housing. On a bike with tight housing bends, it’s also possible that the cable may wear through the liner entirely end up rubbing against the steel housing structure.
Since there are multiple ways the cable and housing system can wear down, with many of them difficult or impossible to see, we recommend replacing the set so you know your bike will be working as well as possible. Of course, if you ever see visible damage – such as a cable fraying or unwinding, a kink or cut in the housing, or strands pulling through the end of a shift or compressionless brake housing – we recommend replacing it immediately.
What’s the best way to prolong the life of your cable and housing if you can’t replace it? Basically, are there any tricks to keep it running smoothly, longer? (regreasing cables, cutting off compressed ends of housing, etc?)
Jagwire: To get the most life out of the system, the best thing you can do is take special care in the setup when you install it. Using stainless steel cables and pre-lubricated housing is a good start. Then, using sealed ferrules to keep contaminants out and lubricant in, can help tremendously, especially if you’re ever riding in wet or dusty conditions. Alternatively, using lined ferrules is a good way to protect a coated cable, by preventing the coating from wearing off as it passes through the exit.
Bikerumor: We get why Jagwire wouldn’t endorse methods of extending the life of your current cables and housings, but there are things to consider. While replacing the whole system will almost always result in the best performance, there have been many times where I personally have needed to improve the shifting on a bike without being able to replace the whole system. From working pro bono on a customer’s bike who couldn’t afford afford the labor charge, let alone replacement parts, to simply not having a long enough section of housing for a frame that runs a full length in one of those situations where you’re working on the bike at midnight the night before you leave on a big trip, sometimes you find yourself in a pinch where things have to be done.
One of the biggest tips I have is that with linear housing, after a while the metal strands start to poke out the end of the housing under the ferrule. Removing the cable and ferrule and cutting the end of the housing off to remove this section will have a huge impact on shifting performance once you install new ferrules in the process. While you’re at it, if you can swing it, I lube up the cable with Shimano SP41 grease (after cleaning the cable with a rag) before reinserting it into the housing. Just a dab on your fingertips and then run the entire length of the cable that’s under housing. SP41 is kind of expensive, but it’s absolutely worth it and the only additional lubricant I will use with cables and housings since it doesn’t gum up or attract much dirt and grime in the long run.
How much of an effect does ferrule choice have on housing/cable performance?
Jagwire: Quite a bit! While a basic brass brake housing ferrule or nylon shift housing ferrule will do the job, it’s worth paying a little extra attention to the details.
When it comes to the material used, we recommend using aluminum end caps whenever possible. These are CNC’d to precise tolerances, ensuring a good fit both on the housing as well as in the housing stop. Even more importantly, the aluminum will not compress under load like plastic ones can – especially considering the precise cable movement needed by 11- and 12-speed derailleurs. They’re also more durable, and better at keeping the housing strands in place on shift and compressionless brake housings.
Beyond the material used, ferrules can have other features to make sure your cable and housing work their best. Sealed ferrules typically have a rubber o-ring placed inside to help keep water and other contaminants out, while keeping the lubricant in the housing. Jagwire also offers “hooded” ferrules, which use a double-lip seal for use in particularly nasty environments.
Lined ferrules have a short liner extending from the base of the end cap. These provide a low-friction solution, as they prevent the inner cable from rubbing against the metal edge of the exit hole. They’re necessary if you want to get the maximum life out of a coated cable, but also reduce friction with a plain, uncoated cable. They can also be used in conjunction with a seal for added protection.
There are even specialty ferrules for more unique situations. “Anti-kink” ferrules are available for folding bikes, externally-routed dropper posts, or other setups where the housing might be forced into a tight bend. There are also many different reducer ferrules made to match modern housing with the wide array of housing stops found on frames, derailleurs, and brake calipers.
What is the best lube/grease to use on cables?
Jagwire: The best lubricant is the one found inside your new, pre-lubricated housing, which is formulated to balance low friction with water-resistance and durability. The biggest difference, however, between original lubricant and anything you add later is in the application itself.
All of Jagwire’s pre-lubricated housing has the lubricant added as the housing’s inner liner is initially extruded. This ensures that there is an even distribution throughout the entire length of housing. While you can get cable-specific grease separately, your only options are to either inject it into cut ends of housing or rub it on the inner cable before inserting it. In either case, you won’t have consistent lubrication throughout.
It’s also possible to add a liquid lubricant to the housing. While this might feel great initially, as it will work its way further into the housing than a grease would, it won’t have the long-term water resistance or overall durability. Many liquid lubricants will also attract dirt, which accelerates the wear even more.
What are best practices to cutting new housing, installing ferrules, and installing and cutting/crimping cables?
Jagwire: I don’t think this is going to be a revelation to anyone, but the key to getting a good, clean, square cut is to use a housing cutter with hard, sharp blades. Beyond that, though, there are a few other details to consider. If you’re cutting traditional coiled-steel brake housing, it’s a good idea to file the end to make sure it’s smooth and squared-off. And regardless of the housing type, you’ll want to open the cut end with an awl to make sure the inner cable isn’t getting pinched. Likewise, making sure the outside is round will ensure the ferrule goes on well.
Once you’ve prepped your housing, make sure the ferrule is firmly pressed onto the end. This is an important step – most of the time when folks “stretch” cables, they’re really just setting the ferrules properly. Most high-quality inner cables are pre-stretched during the manufacturing process, and any sort of break-in of a cable/housing system is actually just the ferrules working their way onto the housing ends. One benefit of using high-quality aluminum ferrules is that they’re better at getting set and keeping everything in place once there.
For inner cables, a sharp, hard cutter is again the key. For anyone cutting a lot of cables and housing, we recommend using a separate cutter for inner cables than for housing. While a traditional housing cutter is certainly capable of cutting an inner cable cleanly, the larger jaw means that cables are always cut in the same spot, dulling the blades at that point. By using a dedicated cable cutter like the Jagwire Pro Cable Crimper and Cutter with a smaller cutting blade will help prolong the life of both tools.
Crimping the cable ends – straight across or an ‘X’ pattern?
Jagwire: Really, all a cable tip needs to do is keep the cable from unwinding, so as long as it stays in place you’re good to go. A single line? Sure. An “X”? Even better! A “Z” for “Zach”? Why not? To the folks that break out the soldering iron to give it a clean finish, I salute you! But I’d be remiss if I didn’t take the opportunity to (again) plug the Jagwire Pro Cable Crimper and Cutter. It’s got an integrated 3-sided crimper that takes any guesswork out of the process and gives a factory-style crimp without going all the way through to the cable – very pro.
How long can you expect to get out of a set of cables and housings? Or when should you replace them?
Jagwire: This is the question we get more than any other, and unfortunately there’s not a definitive answer. Conditions play a big role, with riders in dusty or wet (particularly when salty) places needing to replace more frequently. The system also comes into play – your new Eagle kit requires a lot more precision than the friction shifters on your bar bike, and so will require extra attention. And as alluded to earlier, the cable and housing installation is really important. Pre-lubricated housing, slick stainless steel cables, and appropriate high-quality ferrules go a long way in extending the life of the system.
Since there are so many different ways that cables and housing can wear, and with many of them being difficult or impossible to inspect, there isn’t an easy way to measure wear like with brake pads or chains. If it gets far enough, you’ll feel it with grittiness in the brake lever feel or with shifting that just won’t adjust properly, no matter how much you adjust the cable tension and limit screws. But ideally you’re practicing preventative maintenance with these – if you’re a typical enthusiast rider riding mostly in fair weather, new cables and housing every year with your annual tune-up is probably about right. If you’re riding tens of thousands of miles and replacing chains multiple times per year, you’ll probably need new cables and housing more frequently. If you’re in doubt, check with your favorite local mechanic to take a look and make the call.
Got a question of your own? Click here to use the AASQ form, or find the link under the Contact menu header up top anytime a question pops into your mind!