Recapping how far we’ve come in the previous 7 installments of this series: all the new 11-speed parts are on your road rocket. All that’s left is hooking the levers to the brakes and derailleurs by sizing, routing, connecting, stretching, tightening and capping the cable and housings. Next week will be the final check and tune-up, and you’ll be riding in style!
My first rule of cables and housings is to stick with the ones provided by the manufacturer of your components, i.e. Shimano, Campagnolo or SRAM. I do not recommend using off-brand cables and housings because in my experience it complicates installation, and worse, compromises braking and shifting performance – regardless of the claims of the makers.
Note: We’re only covering old-fashioned human-powered cables and housings. If you’ve got an electronic group, follow the included instructions.
Tools & Materials
Here are a few tools specific to bike cables and housing that can come in very handy.
Bicycle cable and housing cutter: these trap the cables and housings between diamond-shaped jaws in such a way that you get a clean cut every time, and no frayed or squashed cables or housings (with a little practice). Park makes a nice cable and housing cutter, and there are many others.
Diagonal cutter: if you can’t afford a pro cable cutter, a good diagonal cutter can work, such as those from Channellock. They also come in handy for cutting off burs on the ends of cable housings, too, which are often created when cutting. They work well for crimping on aluminum cable caps, as well.
Awl or sharpened spoke: used for sticking in the end of crushed cable housings, and the vinyl liners often inside, so that the cable moves smoothly without drag.
Flat medium file: used for filing the ends of cable housings square and smooth so they fit nicely inside the frame stops or derailleurs/brakes.
Some old sacrificial brake and shift cables: used for getting a clean cut (explained later).
This week’s resource
Park Tool’s chief mechanic, Calvin Jones, wrote this thorough article on cable and housing cutting and sizing.
Brief Cable & Housing Glossary
Brake and/or Shift cable and housing set: usually this includes everything needed (cables, housings, ferrules and cable caps) to connect both brakes or derailleurs.
Cable (also called an inner wire): The wire that runs inside the cable housing and what connects the brake/shift levers to the brakes/derailleurs. Brake cables are large-diameter and have different ends than shift cables, so it’s hard to mix them up.
Housing: The vinyl covered sleeves that the brake/shift cables are routed through. Like with cables, brake housings are larger than shift housings, but can otherwise look very similar – so DO NOT mix them up. Also, shift housing is usually a different design that compresses less than the brake housing for precision shifting.
Strand: cables are made of strands of wire wound together for optimum strength and durability. When a cable frays, the strands are starting to unwind. With luck, you can wind them back in place, but not always.
Cable end or caps: small aluminum caps that are crimped on the end of cables to prevent fraying.
Cable donuts: small rubber O-rings that are available (but not included with component kits) to slide over exposed brake cable sections so that the cable doesn’t strike the top tube when you’re riding and rattle/scratch the paint finish.
Housing ferrule: not always needed (read instructions): these metal or nylon caps press onto the ends of cable housing sections for a better fit in the frame stops, derailleurs and/or brakes and levers.
Tips for easy, proper brake/derailleur cable/housing setup
The first and maybe most important rule for working with cables and housings is to never ever cut them too short. Because, if you make this mistake the only cure is replacing the cable and housing, which can get expensive – and frustrating!
How do you know that a cable and housing is too short? Without experience, you actually might not know. But, the basic rule is that for brake cables/housings, the rear must be long enough so that you can turn the handlebars to steer fully from side to side. And where the rear housing meets the rear brake it must be long enough not to pull the brake off center. It also can’t be too long or it can push the brake off center. And, the front brake has to be long enough so that the brake operates properly and not too long or it can push the brake off center.
Likewise, with shift cables the front housings must allow full turning of the handlebars for steering, but only just; you don’t want huge loops of housing extending way out in front. Also, at the rear derailleur the loop of housing should be long enough so that the housing enters the derailleur adjustment barrel straight on. It’s easy to cut this too short.
It may help to know that even professional mechanics (like me) will typically measure again and again and cut little pieces of housing off, trying to find the perfect housing length. Better to size it little by little like this than cutting it too short and having to buy a new cable and housing. Take your time. You can always trim it later if it’s too long and a buddy tells you it should be shorter.
The second important rule with cables and housing is to check and recheck and make absolutely certain that the cables (inner wires) are not dragging/binding on anything inside the housing. This can easily happen if you cut the housings and crush the end. The cable will then be pinched by the crushed housing and instead of a super silky-smooth cable action, it will be rough. You’ll feel this mistake more when squeezing the brakes than when operating the derailleurs. But you want to avoid it in both.
The way to avoid dragging/binding cables is to cut your housing sections carefully and to never mistakenly put a sharp bend in your cables when working with them. You can flex the cables with the housings as much as needed. But, never actually put a bend in the cable or that bend can drag and bind inside the housings.
My top trick for preventing crushing and crimping cable housings is to insert a sacrificial piece of brake/shift (depending on which housing type you are cutting), inside the housing section at the point of your cut BEFORE you cut the housing. This will reinforce the housing and prevent it from being crushed, and you’ll get a square clean cut every time. You simply poke the leftover piece of cable out afterwards.
Even with my trick, be sure to look at the ends of just-cut cable housings to ensure there is an open, round hole. Sometimes there is a nylon lining inside housing sections that gets crimped shut. Use the awl or the sharpened spoke to poke into the liner and open it.
If the end of the housing is cut crooked, it can sit crooked in the frame stop and brakes or derailleurs. You can square it off with a flat file. A Dremel tool can make quicker work of it, but if you have nylon linings don’t overheat the metal inside the housing and melt the nylon with the Dremel.
Small details can make a big difference with cables and housing, such as whether to place ferrules on the ends of the housing sections. These metal or plastic ends come with the cables usually; however, not all levers, brakes and/or derailleurs require them. The general rule is that if they fit inside the part they should be used to reinforce the housing connection and ensure smooth component operation and optimum durability. If they don’t fit, don’t use them.
Another small detail are the cable donuts that are available to slip over the rear brake cable if it’s exposed beneath the top tube. These prevent the cable from striking the top tube when you’re riding, which can stop a common rattle noise. They’ll also prevent the cable from scratching the frame.
The final detail is the cable caps that finish the cables after cutting to length. They’ll prevent them from fraying and add a nice finishing touch. Usually these are included with cable and housing sets. Don’t lose them when you open the bags.
The key to a proper cable tension adjustment is making certain all the housing ends are seated completely in the frame stops and components and getting the stretch out of the cables. To do this, you route the housings and cables from the levers to the brakes and derailleurs, pull on the ends of the cables with pliers to remove the slack and then tighten the brake and derailleur cable anchor bolts.
This is just the initial cable setup. Next, you squeeze the brake levers firmly several times. You should find that the brakes feel tight at first and then loosen and feel less tight. That initial squeezing has seated the housings in any ferrules, the ferrules in their pockets in the frame stops and components, and has also stretched the cables.
Do the same with your shifting, operating the levers to get the cables to stretch and any ferrules to seat fully. In most cases, with shift cables you’ll find that the cables become slack next to the down tube or along the chainstay for the rear.
After you’ve stretched the cables like this, you loosen the anchor bolts and pull again on the cables to remove the slack and then retighten the anchor bolts. If you did a good job removing the slack and seating the housings, you might never haveto touch the anchor bolts again until it’s time for new cables. Better yet, your shifting won’t go out of whack due to a cable stretching. Though it’s easy enough to fine-tune the braking and shifting with the adjustment barrels – you won’t need to use the cable anchor bolts.
As always, please share your tips and tricks on cables and housings setup to help others with their component upgrade project by Commenting below the Newsletter version of this article.
Next week, in the conclusion of this series, we’ll give the bike a final tune, take a shakedown test ride and perform any last pre-flight adjustments.
Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.