I broke the bike

When I was still working I used to ride my bicycle in warm weather, when the days were long enough that I could wait for the afternoon rush hour to end. There was a good loop in Cummings Research Park, where I worked, so I waited until around 6 pm and then rode 20 miles. On weekends at home I rode down the mountain one way or the other. Sometimes I rode the loop that the Fouche Gap Road Race used last Saturday. Other days I rode in towards town on Huffaker onto Technology Parkway (a grand name without much to back it up). But when the days got shorter and the weather got colder, I stopped riding outside.

We had bought a NordicTrack stationary bike a few years ago, but I didn’t use it much. Then, when I was diagnosed with cardiomyopathy almost two summers ago, I decided to get more serious about it. I figured if my heart was going to get lazy, I was going to push it a little and see what happened. So I started riding about 50 minutes almost every day. Sometimes on Wednesdays I skipped the ride so we could go to our favorite Mexican restaurant for huevos rancheros for lunch, but most of the time I rode.

I wore out the belt that runs from the pedal crank to the resistance mechanism. That was no big deal; I was able to get a replacement for that.

And then a few weeks ago there was a crunch from the innards of the bike, and then no more resistance. I thought I might be able to repair it again, so I tore the bike apart and eventually discovered this.

bearing2

This is an iron alloy pulley that attaches to the resistance mechanism shaft and is turned by the belt I replaced that runs to the pedal crank. Like a typical bicycle rear wheel hub, the stationary bike has a one-way clutch that engages the resistance mechanism when the pedal is turned, but freewheels when the pedal is not being cranked. If you look closely at the picture, you can see that the pulley has a crack completely through. What you may not be able to see is that the clutch mechanism has disintegrated. It’s on the inside, between two sets of roller bearings. The clutch mechanism was made from plastic. I might be wrong, but it looks like it had little plastic teeth that gripped one way but slipped the other. I assume that the plastic clutch mechanism broke because the pulley cracked and released the pressure that supported the clutch.

OK, I thought, maybe I can get a new pulley. So I went online and found a parts diagram with prices for almost every part in the bike. There was an identification number for the pulley, but no price for it. I emailed the service department to ask whether the pulley was available as a separate replacement part. The answer was that I would have to buy the entire resistance mechanism. Sorry.

That wouldn’t be a big deal, except that the resistance mechanism costs about twice what the entire stationary bike costs. It’s more than $800.

I was pretty disappointed with NordicTrack. Iron is a pretty strong material. Steel pulley wheels on automobile engines almost always last for the lifetime of the engine. I probably used the bike more than a typical buyer, but still, I doubt that I actually wore it out. I thought a failure of this type would almost certainly be a manufacturing defect, so I emailed the photo to my brother, who was a materials scientist in a previous lifetime (now he’s a Presbyterian minister). He said it seemed pretty clear that the crack started on the outside of the pulley and propagated inwards. He also thinks the cause was a defect either in machining or possibly in casting.

In the meantime, I started using a rowing machine I bought about 25 years ago and almost never used. I row for about an hour pretty much every day. Leah is also rowing; she’s at about 30 minutes and climbing. Unfortunately, I don’t think I’m getting as much benefit from the rowing machine as I did from the bike. The bike had a calorie display, which could, at least in principle, be pretty accurate, so I had a good idea of how much work I was doing. The rowing machine does not, but based on how I feel using it, I think it’s considerably less energy intensive.

Riding the bike and rowing are both pretty boring. I watch television as I exercise, but with the rower, I can’t flip channels without stopping. Even with satellite, it’s hard to find anything interesting to watch, especially in the daytime.

My brother wants me to keep the part so he can look at it the next time he comes down from Chattanooga. It is an interesting failure, if you want to look at it academically. I don’t much.

I will probably end up buying another stationary bike. I don’t know what type to buy. NordicTrack seems to have a reasonably good reputation, or at least name recognition, but I would hate to buy one and then have the damned thing break again.

2 thoughts on “I broke the bike

  1. That is disappointing to have such a vital piece of the bike break like that. I hope you find a new bike or a less expensive fix for it. I’ve never thought about a rowing machine. I’m going to have to google that to get an image one. The only exercise we’re getting is walking a 3-4 miles a day. Maybe a stationary bike would be a good winter ride for us.

  2. Robin — The biggest problem I have with either machine is boredom. One nice difference for the bike is that you can actually read while you pedal. Impossible for the rowing machine.

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