PreACT Practice Test 5

Spokes

The summer I turned fifteen, the back wheel of my bicycle developed a wobble so bad that the brake pads scraped the rim with every turn. A neighbor told me about the Spoke Shed, a volunteer repair shop in the basement of the public library. The shop which opened only on Saturday mornings, [11] was run by a retired machinist named Mr. Okafor.

On my first visit, I wheeled my bike through the door and announced that the wheel was totally toast [12]. Mr. Okafor smiled and handed me a tool the size of a house key. "We don't fix bikes here," he said. "We teach you to fix your own."

[A] The tool was a spoke wrench. [B] A bicycle wheel, he explained, is held in shape by dozens of thin spokes, each pulling on the rim with a carefully balanced amount of tension. [C] When one spoke loosens, the rim bends away from it, toward the tighter spokes on the opposite side. [D] To straighten the rim, a mechanic tightens some spokes and loosens their [13] neighbors, a quarter turn at a time.

For the first hour, I made things worse. I tightened spokes I should have loosened, and the wobble grew. For instance, [14] Mr. Okafor showed me a trick. He fastened a zip tie to the frame so that its tip barely touched the rim. When the wheel spun, the tip ticked against the rim at one spot on each turn. Showing [15] me exactly where the bend was. By noon, the wheel spun so true that the zip tie never touched it.

Over the next two years, I spent most Saturdays at the Spoke Shed. I learned to replace brake cables, adjust gears, and patch tubes, and I picked up the other volunteer's [16] habit of talking to their bikes as they worked. Last month, a boy of about ten came in with a chain that had broke [17] on his way to school. I showed him how to use a chain tool, and he worked on [18] the chain until the bent link came free. When he finished, he thanked me and rode off before the rain started. [19]