Originally Posted by staehpj1

I agree that it made sense to replace before your tour.

Not sure how you arrived at the 70% number, but I am skeptical of any percentage of wear number derived from measuring the chain. In my experience chains tend to show little to no wear for a long time and when they do they go downhill quickly. Using the method of measuring 12 complete links, I find it is a pretty long time until I see any measurable wear, but once it gets to 12-1/16" it progresses to 12-1/8" (the point that usually damages cassettes and rings) much more quickly, hence the need to keep a fairly close eye on them when they approach end of life.