For another perspective, read the book, "A Bike Ride", by Anne Mustoe. This woman set off on a bike at the age of 50 and rode around the world. She claims she does not even repair a flat, preferring to pay someone else to do it. Her philosophy is that she doesn't repair her car so why should she repair her bike.

While I don't subscribe to her philosophy myself, she is proof that you don't need to be an expert bike mechanic to tour.