Originally Posted by
Athens80
To add an anecdote, my 105 has 21,509 miles since I started recording, with a few thousand miles earlier. I've replaced chains, cassettes, cables and probably prematurely, one chain ring. At a rate of more than 100 miles a year, though less than many BFers. I don't see any indications that this same 105 won't keep working for another 20,000+ miles.
Confused here.. you're saying you've had to replace half of your groupset, but you don't any indications it won't keep working for another 20k miles? IOW parts do wear out