Originally Posted by
cyccommute
..... I installed some in a tire that had been on my bike for a while and they flatted immediately. I had checked the inside of the tire for anything prior to installing tubes…it’s a habit you pick up here in the heart to goathead country…and could find nothing. However when I went out to ride the next morning, the tube was empty. I replaced the tube and checked again before going for a ride. The tire was soon flat again.
This time I checked extremely closely and I found one very, very small burr inside the tire. The burr wasn’t long enough to puncture a thicker butyl tube but it went right though the TPU tube. The TPU tube came with a stick on patch which I used to “fix” both tubes and put one back in a brand new tire. Half way home from my volunteer job (5 miles), the tire was flat. I put in the other TPU tube and rode home. The first TPU was leaking right at the sticky patch. The second TPU tube made it home but was flat the next morning…at the stick on patch.
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Two TPU tubes going flat one after the other- I am going to go with installation error. TPU tubes are very easy to get pinched between the tire and the rim during installation. You have to make sure the tube is well inside the tire when you work the bead over the rim. When you get to the last section where the tire starts to get tight, you need to slightly inflate the tube to about 2-3psi. Just enough to hold shape but no harder. Then, with your free hand, push the tire and tube hard towards the other side while you are prying the bead over the rim.
And when removing the tube- don't just jam the lever in there. The tube tends to cling to the inside of the tire. If you just jam your lever in there and pry the tube will get trapped between the lever and the tire. You need to gingerly pry up on only the tire. Pry it up and down several times until the tube no longer clings to the tire. And then continue on removing the tire like normal.