Alright people, let's talk about your bike and how it functions. Bicycles are wonderful, magical, delightfully simple, and fantastically complex machines of perfection. A model specimen of the fantastically complex component of bicycles - derailleurs. A perfect example of the delightfully simple element of bicycles - cables. Both the fantastically complex derailleurs and the delightfully simple cables must be in perfect, or as near to perfect, working order in order for a bicycle's drivetrain to properly function.In my many years of experience working on bicycles I've come across a particularly interesting thought paradigm that exists in the minds of 90%+ bicycle owners. The thought paradigm is this - "I have no problem spending large amounts of money on replacing, tuning, upgrading my derailleurs but I refuse to pay $4 to $6 (120-180THB) to replace a derailleur cable."
Which brings us to this article. I thought for this month's article I would encourage our readers to ascertain whether they fall in to this 90%+ group or not and then to do something about it. Change your thinking and for God's sake change your cables!
In my experience derailleur shifting problems are caused by:
84% rusted, frayed, corroded cable/housing
10% bent derailleur hanger (rear derailleur)
3% derailleur out of adjustment (derailleur limit screws/B screw)
2% derailleur in wrong position (front derailleur too high/low)
1% bent derailleur (usually because of a crash)
Manufacturers build new bikes with less than awesome cables. This doesn't mean that the new cables on your new bike need to be replaced right away. What it means is that when you've ridden your new bike for 6 months and you're ready for a new set of gear cables, go ahead an splurge and buy the good ones.Most bicycle owners don't do preventative maintenance. In other words, they get things fixed on their bike when it breaks, not before. If that describes you than think about this - bicycle derailleurs work because of spring tension. There is a coiled spring inside front and rear derailleurs and it is the tension of this spring that the friction or ratcheting system of your shift lever is counteracting. Any additional tension created by a corroded cable sliding through its housing causes this spring to work harder, effectively shortening the lifespan of the derailleur.
Guideline for replacing cables:
I know what you're expecting. You want me to talk about riding miles and conditions and how they determine the proper schedule for replacing derailleur cables. Well, I'm not going to do it because my goal is to create an attitude in bike owners that favors preventative maintenance.
Mountain Bikes - Replace your gear cables every 3 months. Use a cable that is stainless or stainless with a teflon coating. Cable housing should be plastic lined and cable end caps should be plastic or aluminum with rubber seals.
Road Bikes - Replace your gear cables every 4 months. Use a cable that is stainless. Cable housing should be plastic lined and end caps should be aluminum with rubber seals.
