Shifting Gears

by David Wolpe on September 20, 2014

On a bicycle one can sweep through a landscape of wind and sunlight and autumn leaves and rounded hills. Below is one of my favorite spots on a favorite ride in New Hampshire:

The Welcoming Homestead

Each time I reach for the shifter on my ride, I have to think about which way to move it. It occurs to me that the difficulties in thinking about this problem have broader implications. The confusion they wreak provides a nice way of looking at the nature of confusion and of understanding, or mis-understanding.

If you’ve ever tried to tell someone new to cycling how to shift — “No, I mean shift down. Down to a lower gear. To make you pedal faster. No, lower gear is bigger. Chain is going up. No, not first gear on the left side. On the right. Shift down…”  then you know what I mean.

Here we have several  ambiguous overlapping concepts:

  • Gear Number: The higher the gear number, the slower the pedals go around, and the faster you are (probably) going.
  • Front vs. rear: ”Your smaller gears are for going faster. In the back. In the front it’s the opposite.”
  • Ring (gear) size: “Your smaller gears go around slower in the back.  In the front the smaller gears go around faster.”
  • Speed of pedaling (“First gear is for faster. No, not the bicycle going faster. The pedals going faster. For when you’re going slow.”)
  • Speed of cycle (“The high gear is for faster. No, not pedal speed faster. Bicycle faster. It’s pedal speed slower.”)
  • Resistance of pedals (for higher gears, it’s higher. Unless you’re going really fast…)

Ambiguous concepts are mud-makers. They muddy up everything from communication to a user interface, to thinking itself.

On the rear wheel, larger rings are lower gears. By lower gears, I mean first and second gear; these lowest are the largest and the easiest. And, in the front, it is the opposite: the smallest is the easiest. Each time you have to shift, you have to remember which way to go (which might be in or out, or up and down, and possibly holding both levers simultaneously, depending on your shift mechanism) and on which side (left or right, which controls front and back). So let’s review: larger is lower is easier on the back, which is right and down or in and both (or not), and smaller is lower is easier on the front, which is left and up or out. Got it?

How can we remember this? In practice, we just get used to it. Or we have little tricks of memorization. For instance, one way to think of the front gears is that they are analogous to your stride. The big ring has a bigger circumference and so you can think of it as covering more ground in one revolution — kind of like having a longer stride. If you memorize this, and just repeat it when you need it, then it becomes habit. Once I was riding alongside my brother and he said to me, “You realize you’re on the big ring in the front, right?” In context he was telling me why it was harder to pedal. So now all I do when I’m confused is remember that admonition. “Big ring in front, harder to pedal.” Or: “Big ring in front. Longer stride.”

So why is that stride analogy true of the front and not the back? I have no idea, and I have no framework in which to think about it. I don’t know where to begin. No wonder that it took about 100 years from the initial Flintstone-esque bicycle to the advent of a chain system, and about another 100 years until the appearance of the derailleur (which switches chains from ring to ring). It is not evident, and this is why the leaps of human invention sometimes take decades or centuries.

I understand that turning the key in my car’s ignition will make it start up. I understand that pressing down on the accelerator will make it go faster, because I’m giving more gas. So let’s for the moment assume that a clear understanding of what is happening, and why, will make it easier to remember.

Maybe there is a place to begin, and that’s the subject of the next post.

 

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