Yes, the wheels are spaced the same, but the little pointy parts that hold the wheelset into the truck are longer on some makes than others. If you put longer axles in the shorter truck, they bind and don't turn easily.Don't they all swim on the same track width? Same distance between tracks or do different makers vary?
Agreed. Wheel diameter difference in N scale is really not noticeable, but the incorrect axle length will cause operational problems, for sure….Yes, there are differences in axle length in addition to the diameter of the wheels. Although, the diameter of the wheels is just a cosmetic difference. The wrong axle length can cause problems