|Joined: ||Sun Feb 17th, 2013|
|Location: ||Friedberg, Germany|
|Which is all true for the prototype, but not for the "tramway" radii used on model layouts. As even the NMRA state in their RP25, tread taper is not necessary for models, whereas proper fillet and flange rounding are. The 'guiding' effect seen on a single truck or car rolling down a straight length of track is due to the fillet, not the taper. Once it is part of a group of cars being drawn along, all guiding work relies on the flanges, especially in curves.