Ok, I was actually counting from the ends of the trucks, my mistake XD but if we are talking about from right under the axle, it is 12 studs. After further investigation, the friction seems to be intensified by the fact that I have 3 cars with the same wheel length. Perhaps weight is an issue? The cattle car from 60052 is fairly light and even though the wheels are at 12, the car actually extends to 20, so maybe that’s why the friction is greater? I wish I could post a picture, but for some reason, my phone says the file is too big.