I had changed over to a 1x from a 2×10 on an old Norco. don’t recall the gear ratio of the old cassette. I had thrown a 10 piece 42 tooth on the back coupled with a 26 up front. Stressed over the decision though. Kept me in a nice granny mode on the climbs. won’t win any races peddling on the flats or downs however.
I’m also running a 28 tooth with a 46 (1×11) on my Knolly. Mush more effective.