Has your team ever been disrupted in their work to deal with a production issue? Has a quick fix ever resulted in the same issue popping up again and again? If so, you are not alone in dealing with the symptom rather than the root cause of the problem. Surely we have all experienced implementing a solution while not addressing the real problem. The following personal story illustrates how frustrating this approach can be.

A few months into 2020 I realized that I wasn't as physically active as I had been before the pandemic. To put it succinctly, let's just say my daily step count was far closer to zero than 10,000. Eager to get active and outdoors, I dug out my old bike, dusted it off, lubricated the chain, pumped up the tires, put on my bike helmet and was off for my first ride in more than 15 years.

I had a blast! I'd forgotten how much fun it is to ride a bike. Over the next couple of weeks I found time almost every day to jump on the bike and explore the gravel roads that radiate out in all directions from our house. Returning from one of these rides I noticed that my tires were pretty worn... and it looked like the sidewalls were cracked and a bit dry-rotted. Wanting to avoid a catastrophic flat and gravel rash that would likely follow, I went to the bike shop to get new tires and new tubes just to be safe.

As a kid, I'd always done my own bike maintenance, starting with my first coaster bike (which I modified with a banana seat and monkey handlebars!), then my Gitane Gypsy 10-speed road bike I got when I was 10, next came my father's gift of his Gitane Tour de France circa 1973 (I still ride on the now 50 year-old Brooks Professional leather saddle that he fitted on that bike), then on to a Trek 7300 Multitrack, the bike in this article. Fitting a new tube and changing the tires would be easy, or so I thought.

Breaking the bond between the old tire and the rim turned out to require a bit of elbow grease, but I was eventually able to separate the two and get the new tubes and tires in place. What a difference the new tires made! On my test ride I felt like I was floating over the gravel.

All was good until it wasn't. Just over five miles into my ride the rear tire lost all pressure. I had to call the Catoctin Mountain taxi for a ride back home. My ever-patient wife, Melissa, arrived a few minutes later to convey me and my disabled bike back home.

When I checked the tire and tube, I found a small hole on the inside of the tube where it rested against the rim of the wheel. I inspected the rim and the inside of the tire. I didn't notice anything amiss, so I assumed I must have gotten a bit of grit or other sharp debris between the rim and the tube when I changed it. A few miles down the road would have been all it took for a sharp little bit of grit to cut into and deflate the tube.

I purchased a new tube and remounted the tire after making sure the inside of the tire was clear of any foreign objects, then was off for a test ride. This time I made it 8 miles and was just a mile short of home when I got that deflated feeling again. Only this time it wasn't just the tire, I was feeling deflated, too. What had I missed? Maybe it was simply a defective tube this time.

Over the next few weeks, I tried another tube and another and yet another. Each time I had to call the Catoctin Mountain taxi for rescue. The tire and rim looked fine, so I figured the tubes must be at fault. However, after half a dozen tubes had failed, I laid the tubes out next to each other for comparison. Each one had failed at the same spot. I looked at the corresponding location on the rim, but I couldn't find anything that might be causing the hole. Still, it had to be the rim.

On the inside of a bicycle wheel rim there are holes cut to allow the spokes to be inserted and tightened. The wheel on my Trek Multitrack is made of aluminum and the edges of these holes can be as sharp as a razor. Normally, tough rim tape covers the holes to protect the tube. On a closer inspection of my bike's rim, I noticed that the rim tape ran awfully close to the edge of the hole where the tubes had developed leaks. My efforts to remove the old tire must have shifted the tape a bit. Even though the hole was covered by the tape, the edge was close enough to the rim hole that the pressure of the inflated tube plus my bouncing down the gravel road must have combined to exert enough force to deflect the old cloth rim tape into the rim hole and expose the sharp edge. If so, it was not a question of whether I would have a flat, just when.

Another trip to the bike shop, but this time I returned with new rim tape in addition to the new tube. I'm happy to say that today, almost three years later, the tire and tube are still going strong. What surprises me about this story is how long it took me to accept the root cause of the problem. I inspected the rim each time and assumed that if the rim holes were covered the rim hole edge could not be the culprit. If I had considered Sherlock Holmes sound advice in The Sign of the Four:

"when you have eliminated the impossible, whatever remains, however improbable, must be the truth",

I would have replaced the rim tape after the second flat.

When was the last time you or your team were disrupted by a production issue? Did you just buy a new tube or did you also replace the rim tape?

FoxHedge Ltd Blog

Dealing with root cause: Lessons learned on a bike

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