4 1/2 in is more commonly referred to as 110mm for this application. The problem is that axles/hubs for those wheels are splined not smooth and keyed, and certainly not in an inch measurement. So where I see this is you have 2 options if you want to use those wheels: a) Buy splined hubs and have them machined to fit the 1in axle you have, or b) get an ATV axle with 25 spline ends and use the commonly available hubs.