Changing the chain when it less than 0.5% worn?
Had my bike at the shop for repair for reasons other than the drivechain. Was told that my chain was worn out, would I want it replaced. I said no, I have a spare new chain at home. From what I can gather he says the shifting was poor because of the chain. The chain probably has 7,000 miles on it. I checked with the Park chain wear tool, and it's not 0.5% worn yet. I don't distrust the bike shop's opinion, but I had always thought it was a matter of just checking the stretch on the chain. Should I be changing chains more frequently than the wear indicator suggests? What are some good rules of thumb here. This is an 11 speed Shimano 105 groupset.