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Pay Attention to Moving Parts

Safety Corner logoby Eli Post


So many of us take our bikes for granted. We haul them out of the garage or basement, and hop on ready to ride. We forget that the bike is a machine with moving parts that can wear, and that in certain situations an unexpected mechanical failure can have safety repercussions.

To cover this subject fully would require more space than we have available: How do you avoid crashing due to a mechanical failure. What preventive maintenance will avoid mechanical failures? Cables, especially brake cables, can fail, brake pads wear out or become misaligned, forks, especially carbon, can become compromised, spokes fail, handle bars or seat posts loosen, and we all know the terrifying pop of a blowout.

By way of illustration, we will share one story with you. Have you ever considered what might happen when a chain breaks? We suspect you never thought of that at all. Chains just lengthen with wear, right, and wear out cassettes? Here is what one of our members experienced.

Hi Eli,
Today my riding buddy and I had a freak accident during our 18-mile lunch hour ride. Nothing appears to be broken on his body and I’m as good as ever, or at least as good as I was yesterday. While we were pedaling up a slight incline approaching the front of Wakefield High School heading west, Steve’s bike was in a high gear traveling at about 16 MPH. He was standing and pumping hard. Suddenly his chain broke and like a rock he came crashing down on one side of his handlebar. The impact jerked his front wheel left and dumped him on the ground to the right. Because I was about a bike length behind him I almost ran over him, but cut sharp left and fell too, but controlled my fall doing a tuck and roll of sorts. As soon as I came to a stop I leaped up and out of the right lane back onto the shoulder. To my amazement I wasn’t scratched or bruised anywhere. Steve has some pretty significant bruises, scrapes and a very sore right shoulder, but nothing seems to be broken. Why did the chain break? I can’t answer with total confidence, but I know that this chain probably had over 2000 miles on it, that Steve removes the chain with a chain tool each time he cleans it and the last time he cleaned it was less than two weeks ago. One of the pins seems to have migrated to the point where one of its side plates came loose. Once that happened, the pin, which was now only attached to one plate, pulled out of the companion link, separating the chain under tremendous force. Down went Steve.
Thanks, Bill Fanning

Another rider who also experienced a chain break reported, “Prior to the chain break, I noticed my derailleur skipping between gears and feeling rough. I assumed that a cable adjustment would fix it, and I adjusted frequently as I rode. I should have looked at the chain.” The Web is filled with helpful information about chain repair and replacement. SRAM, for example, sells its chains with a Power Link, which allows the chain to be separated and removed for cleaning and lubrication without pushing out a pin.

More importantly however, you should remember that bicycle repair and maintenance is crucial for safe riding. There are certain parts of a bicycle where a single failure can cause a crash. The chain is one example, but the handlebars, stem, and front fork could potentially fail and put you in harm’s way. We will have more to say about other mechanical failures in a future article.

Safety is about choices. What choices will you make?

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