Speaking of changing tires. I got 5,672 miles on my first rear tire with no flats. Back in October, the new one caught a tiny glass shard after 1,595 miles. Replacing the tube was easy, if a bit slower than on a normal bike. It was the middle of a nice afternoon, in the mid 60s F. I noticed the back starting to feel a bit squishy, so I pulled over, using the front brake. I pulled it up onto a nice grassy spot, putting it on the center stand on a spot where the rear wheel was slightly off the ground. I hand cranked it into the smallest chainring, and rear sprocket, and undid the derailleur mounting bolt, moving the derailleur and chain aside. I removed the two velcro cargo straps, holding the wiring bundle to the left rear chainstay, and the stretchy Grin Tech connector sleeve covering the bundle. I undid the phase wire, hall, and thermistor connectors. I removed the torque arm bolts, and loosened the axle nuts. Then dropped the wheel down, and slide it out. After finding the offending glass shard, and removing it, I pulled the tube, and found the tiny pinhole. I got out a new tube, and reversed the whole process.
Yesterday was a bit different. 1,953 miles after the first glass shard, I picked up another. Backend felt squishy, front brake, pull up on grass, find and remove glass. However, now it is late December, upper 30s F, about 45 minutes until dark, with temps falling. The idea of fixing a flat with cold hands, and no flashlight, this late, was not my first choice. I had 10.5 miles to go. I figured I'd see how long it would hold air with the glass removed. I put in 250 strokes on my old Topeak Road Morph to get to 75 psi. I noted the time and distance and took off. Running 22-23 mph, I got 2.5 miles before I felt it getting soft. Stop and repeat. I stopped again at 2 miles, as I was going to get on the old state highway. I pumped it up, and with 6 miles remaining, I figured I'd push it up 28-30 mph and get probably 3.5 miles before needing to stop. Worked like a champ. The last pumping got me home with air to spare, as the sun disappeared. Ten minutes after parking the bike, the tire was completely flat.
So today I installed the new tube in the comfort of our back room. I decided to try something new with the old tube. I have heard that thick tubes don't really help much. I suspect once the rubber is pierced, under pressure, the nick acts as a stress riser propagating through the tube. I removed the valve stem and its base, and slit the old tube along its inner surface. I slightly inflated the new tube, and slipped the old tube over as tube cover/tire liner. It installed just fine. I will see tomorrow how it goes. Sometimes, hard tire liners abraid the tube, and actually cause a flat, but the old tube is soft, just like a rubber rim strip. And I figure if a sliver pricks it, the hole won't propagate into the tube. We'll see.