Just a musing and perhaps a warning to others.
I’m up around Pately Bridge for 5 days mountain biking on the grouse moors, which by the way are on fantastic well maintained bridleways. Fettling the chain last minute before setting off, the gauge said that it was warn so I fitted a spare new one. 100 yards into the first ride I had terminal chain suck and realised I should have changed the chainring as well as the chain. I had spare chainrings at home ( this is an EMTB with a Bosch motor) so I drove the 60 miles home and fitted a new chainring.
I don’t know if anyone has guessed but 100 yards into the next days ride and the chain is jumping like mad on the rear cassette. Despite being a common Shimano cassette the local, quite large, bike shop had nothing in stock.
So, I’ve done three days climbing on only four non slipping cogs. The moral being, “one off all off”.