On Tuesday, October 2, 2018 at 1:10:59 PM UTC-5, jbeattie wrote:
O.K., reality check. I was riding in with my son this morning, and he had a sudden attack of ghost shifting or skipping of some sort. I was watching his rear wheel (my usual position, hunkered down behind him), and I didn't see chain skip.

IME, ghost shifting usually happens with a sticky cable at the BB, but what is the likelihood that this is a casette/chain issue? I changed the chain but not the cassette a month ago. It worked beautifully -- no skipping, but I'm wondering if you can hit a tipping point where the cassette goes and the chain is O.K., and you get shift issues. If the cassette is too worn, I usually get problems the moment I put on a new chain and not later.

-- Jay Beattie.

It is October, the month of ghosts, after all.