This is the great thing about bikes, its not like a car or truck engine, the various bits and bobs are fairly easy to work on--IF of course youhave the interest and apptitude.
To me, this was always a priority, to learn how to do all my own stuff, and therefore know personally how everything is, in great shape and also to know what to look for, to listen to, etc to pick up any issues well before they do become a trip stopper or an inconvenience.
I certainly have made lots of mistakes and messups doing my own mechanical work over the years, but this is how we learn, and Im sure I'll screw up again---but this is life, and the main thing is that we get better and more knowledgeable about bike mechanical work , and my experieince has certainly shown that by being knowledgeable and knowing your bike inside out, it goes a long way to REDUCING the risk of a problem.
That is exactly why I started the thread. It is interesting to hear of other situations others have been through on a tour. It gives me some ideas on things to look for with my own gear, but also contingencies.