As you sit there at your computer, wistfully pouring over images, specs and reviews of new bikes, there are all sorts of things that catch your eye: frame materials and geometry, weights, components, wheel aerodynamics – you name it. Despite their importance to overall performance, though, cables and housing usually don't even earn a line on the spec sheet. They're some of the most often overlooked items on a bike and yet your bike doesn't work without them. Plus, they're one of easiest ways to extract — or ruin — a bike's true performance potential.
Cables and housing – the lifelines of your bike – translate input at the controls into an output at the other end. If you're not going to install them correctly or you decide they're not worth any investment, you may as well just go with components two levels down from what you bought because that's how well everything will work.
For the sake of argument, let's say Dura-Ace ranks a '10' on Shimano's performance scale, Ultegra is an '9', and 105 is a '8'. Now let's say a top-end cable set takes that Dura-Ace shifter's '10' input and translates that to a '9.5' output at the rear derailleur.
Suppose you want to cut some corners to save a few bucks on cables and housing. Now that '10' input could perhaps yield just a '8' output. Congratulations - your shiny Dura-Ace now performs like 105.
Despite what you may think, this is an all too common scenario.
The two main enemies here are friction and compression. Friction (usually caused by poor quality cables and/or housing, or poor cable routing that creates bends that are either too tight or too numerous) steals part of the signal you're trying to send, like a bad game of 'telephone' down the row of a movie theater.
"Oh, you wanted to shift three gears? Sorry, I thought you meant two. My bad!"
It can also make a lever harder to operate than it should be, robbing the crisp and precise action you thought came stock with that new pair of shift levers or fancy new brakes. It's for precisely this reason why electronic and hydraulic systems work so well – no loss of signal (at least in theory).
Compression problems, on the other hand, are most apparent on cable-actuated brakes with long lengths of housing. Squishy housing means that the panicked effort you're putting into your levers en route to that nasty precipice over the side of a switchback isn't translating directly into more clamping force at the rim. Instead, you're merely shortening the housing – and gaining a lever that feels like it's connected to marshmallows.
Many of these issues can be avoided with a careful initial setup: proper housing lengths and caps, clean cuts with appropriate tools, etc. But upgrading the cables and housing themselves can yield remarkable results. Gore's sadly discontinued Ride-On sealed sets are incredible at reducing friction while the compressionless Yokozuna Reaction stuff does wonders for lever feel, particularly with cable-actuated disc brakes.
Sadly, though, poorly designed cable routing can't be so easily remedied. From a design standpoint, routing shouldn't be an afterthought, exasperatingly ironed out after all the sexy work is done. When executed well, the cable can move through the housing with minimal friction, it's protected from the elements, and replacement doesn't require an entire afternoon. The best routing also keeps everything away from your body and doesn't rub on the frame.
When done wrong, however, it can take the most brilliantly designed machine and render it frustratingly hamstrung by a critical flaw that can't easily be fixed. Are you a bike mechanic at a TT/tri shop? Heaven help you, my friend.
So what's the point of all of this? Stop ignoring your cables and housing, people! This isn't a conspiracy to get you to buy more stuff. In fact, I'm trying to get you to buy less stuff. Seriously, folks, quit trying to buy your way out of a problem that's so easily fixed. You might be amazed at how well that bike of yours might actually work with a little cable and housing TLC.
James Huang has been writing about bicycle tech since 2005 and has more than 14 years of experience as a shop mechanic. In that time he's seen plenty of fantastic gear and technology but also a lot of things that have just flat-out pissed him off. Follow the AngryAsian on Twitter at @angryasian, and check BikeRadar for more of his columns soon.