My wife and I both ride Specialized Crosstrails and love them. Hers is a 2014 Sport disc and mine is a 2015 Expert Disc. They each have roughly 750-1000 miles on them. Im meticulous about maintenance and cleaning. Our chains get a good clean and lube every 100 or so miles or riding. 99% Colorado bike path and roads.
My question is this; how often should I think about replacing the chain on our bikes? My wife's is not shifting as crisply as it used to (could be lower components etc...) and Im trying to get my head around why? Thanks.