Events of the past few days have established that my punctures are not being caused by protruding spoke ends, even thought all recent punctures have occured on the inside part of the tube where it is next to the rim tape.
I recently installed some good cloth rim tape, yet, on pumping it up, it developed an immediate puncture without me even riding it.
The puncture was again on the inside part of the tube and directly over a spoke nipple.
In desperation I decided to beef up the rim tape even more by making a second layer of rolled newspaper; the idea being to take it for a ride to confirm or deny the theory that spokes were causing the puncture.
I installed tube and tyre, then left them, planning to go for a ride a few hours later.
A few hours later I found the tube had developed another puncture, again on the inside next to the seam.
I repaired the puncture, pumped up the tyre, and, seconds later, it punctured and deflated (again on the inner part, again near the seam, but this time between two spoke nipples, not over one).
At this point I decide that the tube must surely be defective, put it in the bin, removed the newspaper rim layer; then installed a different (though not new) inner tube.
I pumped it up to 55 psi with the track pump and put it to one side.
Seconds later it deflated!
This time the damage with a three inch slit in the tube, running along the seam.
I conclude from this that spokes are not the cause (as all these punctures have happened without the wheel being ridden, and at tleast two while there was both cloth rim tape and thick paper between the tube and the spokes).
So I’ve tried to do some lateral thinking about what things I’ve been doing different during this period of very excessive punctures.
Then it occured to me- I bought a track pump.
I did this because of several consecutive punctures which I believed were ‘pinch flats’ (so I thought my tyre pressure was too low and bought a track pump).
I now believe that these were not pinch flats at all, as the distictive short line of holes matched a defect I found in the tyre.
All the punctures that happened after that (since I repaired the tyre defect) have been of a totally different kind i.e. on or near the inners seam.
So I’m thinking, could it be that excessive pressure is blowing the tubes?
Though the tyre is rated 40-65 psi, maybe, for whatever reason, my combination of tube and rim just can’t take it.
Equally possible, maybe the pressure guage of my new track pump is defective, and I’m actually going way above the 50-55 psi I’ve been trying to achieve.
What I need to do next is repair the tube and pump it up to the pressures I used to use (i.e. use the hand pump) and see if the punctures stop.
Also maybe buy a pressure guage to see if it agrees with the track pumps readings.
But I’m just wondering if-
the above reasoning seems plausible
for those of you with lots of inner tube experience, in situations where a tube is wrecked by being overpumped whilst in a tyre, does the hole tend to occur on, or near, the seam?