I was riding through the park on one of the first summer evenings when I first noticed it: a looseness in my pedals.
It was a mild looseness—I couldn’t see it, I could only feel it. With every half rotation of the pedals, when it came time for one foot or the other to press down and urge the bike forward—that’s when I felt it. Instead of my foot meeting the resistance of the pedal, there was nothing. And then, a millisecond later, there was the resistance of the pedal.
It happened on every rotation for each foot. As with many bike troubles, the annoyance lay not only in the trouble itself, but in the fact that I anticipated it every time my foot pushed down. As the red sun set on me, I sang songs along to the rhythm of my hiccuping pedals.
The next day I woke up to ride my bike again, hoping that the issue had resolved itself overnight. But as soon as I pushed off again there it was. Bikes are not people, I reminded myself, they do not heal themselves.
I stopped at a bike shop run by one lone mechanic overworked to exasperation. “It’s biking season and we are up to here”—he made a line with his hand in the air over his head—“in work.” But I convinced him to take a look and give me a diagnosis. He gave my pedals a little tug and confirmed what I already knew: yep, they were definitely loose. He pulled out a tool, tightened them up, and off I was, singing his praises.
But it turned out to be just a temporary fix. A few days later the strange looseness returned, haunting my every pedal stroke. So back to the mechanic I went, but a different bike shop this time. Even though the shop was swarming with customers, a young guy took the time to put my bike into a stand, pop open the bottom bracket and check out the bearings.
His suspicions were confirmed, he said, the bearings–the things that allowed my pedals to turn–were dry. Parched, in fact. Normally the bearings are packed with grease to equalize pressure and make things run smoothly. But mine had no grease.
“It’s good you stopped here,” he said, “your bearings look okay.” They were shiny and still perfectly round. If I had gone much longer without grease, they would have started to wear. The parts in a loose bearing system wear together; if one part of the bottom bracket (the bearings, the cup, or the cone) is damaged, it won’t be long before other pieces start to wear as well. Bearings with dents or holes need to be replaced immediately.
Bearings are what allow the bike to move. There is a bearing system in each of the wheel hubs, the bottom bracket, and in the headset, which allows the handlebars to turn.
Most older bikes, and some new bikes, have a “loose bearing” system: you can open up the shell—made up of a cup on one side and a cone on the other—and theoretically dump the small shiny balls onto the floor, if they aren’t packed in there with grease.
Some new bikes have a cartridge—a bearing system that is sealed shut. If it stops working, the entire cartridge usually needs to be replaced. This isn’t necessarily the case with loose bearings, where you may just need to replace a set of bum bearings.
If your pedals feel gritty or wobbly, or if you can hear them grinding, it’s a sign you should check on your bottom bracket. Elsewhere on the bike, if your wheel is tightened to the frame, but it still feels loose, your hub bearings may need some attention.
But dry bearings can be a silent killer–you may not notice if your bearings need grease. The best way to prevent your bearing system from getting thirsty is to take your bike to a mechanic for a yearly tune-up. Although a bearing check is not included in the basic tune-up, and the bottom bracket may go several years without needing to be re-greased, when the mechanic takes a look over the bike, he or she will know whether or not it is worth cleaning out your bearing system.
I rode away from the shop that day, my pedals spinning without a glitch, and a greater appreciation for the dark depths of my bicycle that allow its two wheels to keep on turning every day.
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