I wrote the following in the middle of the night before you had received any replies. I decided I was way too tired to be posting anything, saved a draft so I could check it after some sleep, make sure it wasn't incoherent.
Search "effective gear ratio". You would need a higher numerical ratio (commonly, and confusingly, referred to as lower gearing) with a large OD tire than what you would need with a small OD tire, so you may need 7:1 or 8:1 (or ?). Judging from that small sprocket, I imagine the wheel came from something with a motorcycle type engine which would have had a primary reduction (crankshaft to clutch) plus the various gear reductions of a multi-gear transmission. I imagine you would need a sprocket nearly as large as the wheel rim if you're going direct clutch to wheel (notice how many minibikes have a rear sprocket around the same diameter as the wheel).
Here's a handy sprocket diameter chart. It doesn't list #41/420 but they have the same pitch as #40.
https://www.rollerchain4less.com/sprocket-diameters
I'm not 100% certain but I think if you had two bikes that were identical (same engine, clutch, etc.) except for different size wheels/tires, they would need to have the same difference in sprocket to tire radius (see sketch below) to have similar performance. If I'm wrong, anyone more knoledgeable feel free to explain why.
View attachment 261748