I am wondering if it's normal for a wheel to go out of true when it is loaded down for a tour. Last May I had the wheels trued by the LBS as a part of a tune up package before doing a 10 day tour. After the first 40 miles, my back wheel was significantly out of true. (Luckily I had a spoke wrench and it was an easy fix).
Second question: Either before the tour or after (I can't remember!!!) one of the spokes randomly broke (I only ride pavement). The LBS told me the wheel may not have been properly tensioned by hand, and the factory/machine tension is usually not sufficient even if it's trued. Is that accurate? and could there be any connection between the lack of proper tension and a true wheel going out of true from a loaded rack?
I'm trying to treat these as two separate questions since i don't remember if the mechanic trued it all up before the spoke broke or after.
Any insight is appreciated, you don't have to lay out all the wisdom of wheel science but I am just curious about this stuff. Depending on finances, I may or may not take a wheel building class before my tours this summer, and your responses will probably guide whether I do that.