Posted May 1st, 2010
A close relation of mine, we’ll call her Mustard, recently announced that she is moving far away in search of new scenery and new opportunities. I am happy for her, but I’m going to miss her. She’s selling all of her furniture, but her really sweet couch is mine for free if I am simply willing to adopt Mr. Jackson, her crazy old cat. I am currently weighing my options. Do I really want the couch that bad? Do I really want a crazy old cat who finds the bathroom sink a suitable place to take a nap? It is a really sweet couch, so I’ll continue to mull it over. But today wasn’t about Mr. Jackson or the couch. Today was the most perfect spring day ever, so we just went for a bike ride.
Mustard rode her flat-bar performance hybrid that I gave her for her college graduation present. It is the perfect bike for cruising along the Burlington bike path and similar paved bikeways and roads. The 700c wheels and road tires roll smoothly and efficiently, while the flat handlebars provide the optimum handling required for weaving between walkers with ice cream cones, young ladies with jogging strollers, and old ladies with three dogs that sprawl out on their leashes in every direction, like octopus tentacles.
Mustard’s bike hadn’t been ridden since last fall, so I told her that she can count on the tires needing air. Air doesn’t like to sit around. It has better things to do. Just like watering a plant, if it has been a few weeks, or months, don’t even bother checking, just grab a pump, or a watering can, and get to work. And just like a plant, if it has been a few years, your tires will be dead. Sure enough, her tires were way down, so we pumped them back up to their recommended PSI, which was indicated on the sidewall of her tires. I then told her to ignore this step if she enjoys the feeling of dragging a log behind her, or if she likes getting flats.
I rode my steel 29er hardtail mountain bike. Not because it was the ideal bike for this particular ride, but because mountain bike season is still many weeks away, and I can’t wait that long. Aside from my tires being low, my rear derailleur cable was a bit slack. Just as tires lose air, cables lose tension, so I spun my barrel adjuster a bit until the shifting was precise. If you are willing to consider adopting a crazy old cat, I’ll explain how I did it.
Your shifter tells your derailleur what to do. The derailleur cable is the line of communication, so the first thing to check is whether the line is clean. You can easily do this by unbolting the cable from the derailleur itself. Grabbing the cable with your left hand, gently pull in the direction of the anchor bolt. With your right hand, click the shifter back and forth. The cable should move freely in both directions, with minimal friction. If it doesn’t, you need to figure out why. Perhaps, because you left your bike in a snow bank or in a damp basement all winter long, the cables have rusted.
This little exercise will also show you what your shifter is really doing: with each click, it is pulling or releasing a small amount of cable, which, as you can guess, is exactly the distance between the cogs of your gear cluster. With a standard rear derailleur, when your shifter pulls cable, the derailleur will move inward, towards the larger, or lower-geared cogs. Releasing cable from the shifter allows the spring of the derailleur to move it outward, towards the smaller, or higher geared cogs. Now is a good time to mention that I meant to say that Mr. Jackson is a nice adult cat, not a crazy old cat.
While the cable is still unattached, you can dial in your derailleur’s starting position. The starting position is when the top pulley of the derailleur is centered under the smallest, or highest geared, cog of your cluster. To center the pulley under the highest cog, simply turn the high limit screw, generally identified with an “H” in or out until the pulley’s teeth are directly in line with the cog’s teeth. You are now ready to bolt your derailleur cable down. Making sure you’ve released all your cable from your shifter, bolt the cable down while tensioning it with your free hand. Don’t pull too hard, just enough so that there is no slack in the line. At this point, when you click your shifter, the derailleur will move so that the top pulley is now perfectly centered under the next cog. If it is slightly off center, spin your barrel adjuster in the direction that you want the pulley to go. With this fine tuning complete, your bike should purr like a nice adult cat.
But it probably won’t. There are no fewer that three thousand factors that can affect precise shifting, even though you’ve followed the steps above. A bent derailleur hanger, a tired shifter, a worn out chain, a burr, and loosey-goosey derailleur pivots are just a few, and those require more advanced skills to remedy. A more common and easily remedied factor is proper lube and shifting techniques. A light, barely detectable coat of bicycle chain lube on clean chain is what you want. A dark, dripping coat of motor oil on a dirty chain, which will only attract more dirt to your chain, like a nice old cat to your lap, isn’t. As far as proper shifting, it takes a lot of practice, but there is one fundamental rule you can start following today, unless you want to break your chain or bend teeth on your cogs or chainrings: do not shift when your chain is under a lot of tension.
Now about that crazy old—I mean, nice adult cat…