We biked to some errands on an unseasonably warm 4 January and, a few days later, I noticed the rear tire on Mary’s bike was flat. A bit of Quality Shop Time later:
On the upside, I found it in the garage and fixed it in the basement.
The chip emerged from one of two adjacent gashes in the middle of the tread, but hadn’t quite cut through the tire. A somewhat larger chip (that’s a 0.1 inch grid) in the other gash cut through the Schwalbe Marathon’s protective belt to puncture the tube, then fell out.
The rear wheel of her bike now sports a Michelin Pro-Tek Max tube inside a Schwalbe Marathon Plus tire, as does mine. The wheel + tube + tire probably weighs as much as some entire carbon-fiber bikes, but it doesn’t matter.
Searching for the obvious keywords will produce many other instances…