Were do you get gear reduction for a 2011 Honda 420 rancherThis may get moved to the gear reduction sub section.
Realistically speaking to keep power the same you’d get away with 27 to 28” it’s difficult with a Rancher because there’s no invetween reduction, I’m pretty sure you got a 35% or 69% available.
It all depends how much deep mud you ride, with 28 mayhem’s and the 35% your probably still going to have to use first in deep clay mud holes. However, if you ride more flat trails to get to these mud holes then a 35% is more suited and just put up with having to use first gear. The 69% would give a super slow ride on trails with 28’s, you could go up to 30 to 32” though with the 69%.