Flawed chain length logic, or not, as the case may be?

N0bodyOfTheGoat

Back at the end of September, I fitted a new chain, but made a bit of a mess of it (removed two too many links for 38T chainring with 11-34T cassette, but fortunately I had an 11-30T on my skinny wheels, so been using them since).

Last weekend, I replaced the 38T chainring with a 34T Ringmaster.

Is my logic flawed, that technically speaking...
That same chain, as is, is now strictly speaking a little slack for the 11-30T cassette?
I could safely now install the fat rear wheel which has that 11-34T cassette on it, because the chainring is now has 4-teeth less, without risking a derailleur in wheel spokes moment if I ever selected the 34T sprocket?

keef66

4 fewer teeth at the front and 4 more at the back, so you are maintaining the status quo surely? Try it carefully on the workstand first though; you'd not want to find out the first time you select your lowest gear stomping up a climb.

The Rookie

Agreed, the wrap has been changed by 2t at each end, young and yang, so yes it should work fine.