After my flat tire disappointments the last two weekends, I decided it was time to take action. So this evening, I spent some time at the kitchen table with a couple of patch kits and a pile of tire tubes.
I don’t mind patching tubes, it’s easy enough to do. And I don’t mind riding on them, either. I have in the past ridden on tubes with as many as four patches, and that held together fine. Some biking acquaintances tell me they’ve put on even more — one guy said he was happy riding on a tube with a dozen patches.
It turns out I’ve been slipping in my repair routines. I had several tubes in boxes — not their original boxes — stacked in a cabinet in the garage. I’d marked the condition of the tube on each box, so I was able to grab a new tube to replace the one that flatted on me Sunday. But I like to keep a stock of patched tubes handy. Several of the boxes indicated that their tubes needed patches. Wonder why I didn’t attend to that some time ago?
I carefully examined each tube by eyeball — then inflated them and took them over to the kitchen sink, which I had filled with water. One by one, I submerged the tubes to find the telltale trail of air bubbles that indicated a leak. Some of the leaks were so tiny, they were hard to see — even after the bubbles told me where to look. That’s what happened with the tube I used Sunday. I patched one puncture, but missed another one altogether.
I hope my efforts have paid off. I’ve got a new tube in the tire of my bike, and a freshly patched tube in the seat bag, ready for use in the future if I need it. And in that cabinet, three other patched tubes in their boxes — labeled “OK.” I hope they stay that way.
Using the patched tube as a spare and the new one in the tire is a bad idea. A failure of the patch is quite probable. If the repared tube fails in the tire, you take it of and use the new tube, which will hold air. If your spare tube fails, you will net know it until you need it… And then you’re screwed. (this is called a “dormant failure”, and that’s one of the main concept in airplane safety: this type of failure is why many back-up systems like back-up fuel pumps are tested before each take-off)
Moreover if you use the patched tube in the tire, the next time you have a puncture you will have one tire without patch and one with two patch. And then one with three patches and one you can still trust. If you use the new tube in the tire, you will end with two tubes with a higher probability to fail.
Bike Noob says
I don’t disagree with your reasoning. My experience is that patched tubes work well. Since I also carry a patch kit with me, even if a patched tube does fail, I can re-patch it and get home without complications.
If you’re reading this and aren’t sure how to patch a tube. Visit my Blog for a video on how to do that!