So your bike isn't shifting properly? OK. Come in, sit down, we can talk about this.
Now, now, tell Uncle Knuckler everything. Oh, so it skips around. It takes two clicks to get it to shift. Anything else? It's driving you crazy. Last question, when was the last time you changed your cables/housing? Six years ago? Holy shit, let's start there.
There are three parts to most shifting systems: (the exceptions are Di2 and that new Syncros stuff) the shifter, the cables/housing and the derailleurs. The shifter is where your input is applied. Want a harder gear? You hit the button releasing or pulling cable tension. The derailleur receives that input via cables/housing and moves the direction that you wanted it to. It's a simple system.
The weak link to the system is the cable/housing. Over time grit and shit will enter the housing degrading the inner sleeve causing friction. The outer sleeve of the housing will also wear exposing the inner radials adding flex to your system. Sure you can buy that fancy Gore stuff to extend the life of your cables but one thing is certain, your shifting performance will degrade over time, regardless of what you do. Yes, I said regardless of what you do, at some point your bike is not going to shift like it should. Big fucking deal, get over it and buy some new cables/housing. How often? Well, if you need me to give you an exact time frame, once or twice a year. If you think you can handle a little more freedom, change them when your shifting isn't working perfectly.
One thing is certain. If you walk into your local bike shop, tell them that your bike isn't shifting properly and they suggest cables/housing (notice how they always go together. I think they are in love) do it. It won't cost you very much and it is something that probably should be done. I can't count the times I've been told, "but I just changed it." OK. Then why are the radials popping out of your housing and the cable's all rusted? Oh you drove through a rain storm, power washed your bike. Got it. Cables/housing changed. Problem fixed.
So you are convinced and you want to do it yourself. Let me give you a few tips. Not that kind of tip you sick bastard...
If you don't have the proper tools don't start this project. You will need cable cutters, sharp ones that actually work. If your cutters are rusted or fray your cables, you may as well have left the old, shitty cables/housing in place. Also required, are a 5mm Allen key and a sharp object. The sharp object will be used to ensure a good opening of the end of the housing after it is cut or it can be used to shove in your eye if you fail to follow the instructions.
Routing is important. If this is your first dance, pay attention to how the cables are routed before you cut them off the bike. Improperly routed cables will cause problems.
Length, regardless of what she told you, is important. A good rule of thumb is to turn the handlebars until they are parallel to the top tube. If your cable reaches this point, it is long enough. Conversely, if the cable is extra long at this point, it is too long and should be shortened.
The cut of the housing is important. You want a good clean cut that is perfectly perpendicular. If you want to get real serious up in this place, you would take a file or grinder and "finish" the end. The ferrules (housing ends) are also important. I personally prefer the Wheels Manufacturing ones. Made in the USA and well made at that.
Unless you live in wet weather, skip the lube. Modern housing is slick enough without and grease will only make your shifting feel sluggish which is kind of what we are trying to avoid all together.
Derailleur and Brake housing are different and should not be interchanged. You can find housing that claims to do both but it doesn't do both well. Avoid it.
When in doubt use your reference material... Sheldon's take on it.
Or you can avoid this entire problem all together by buying Di2.
Now you can go ahead and get off my couch. It's starting to get awkward in here and I want to go home.
“Put a fork in me-
8 hours ago