I have about 9000 miles on my bike and the only things I have replaced are tires, tubes and bar tape.
The question is, should I replace my chain now? I clean it very often with the rolling scrubber type chain cleaner and water soluable degreasers and keep it well oiled. I have been checking it via the 12 inches from pin to pin method and the chain only shows about 1/32" of "stretch". The shifting and smoothness seem the same as always, no troubles at all. I have inspected the cassette for wear and only see very little difference on the cog I seem to ride in a lot. I noticed that not all the teeth on the cogs are shaped the same, I suppose that helps with the shifting?
I know the general consensus is like 2-3000 miles for replacement, but given my experience with this bike it doesn't seem necessary.
The group on this bike is Shimano Ultegra with 9 speed cassette.
What does a chain and cassette usually cost to replace?