@AlanRail posted:There are many factors that cause metal-on-metal to wear. Here with Super "O" you have rotating steel on copper that is conducting electrical current. However, the same is true for steel on steel.
Under such conditions, a form of damage known as “galling” is common; this is thought to occur by gross plastic deformation, atomic bonding (or cold welding), then fracture on one or both surfaces, leading to material transfer. Galling, however, is not the only form of damage encountered in unlubricated sliding systems.
There is also "oxidative” wear. This is usually caused in high temperature sliding but can also be caused by electrical currents passing between metals at lower temps. This is not common as most sliding occurs without electrical transfers.
Thus, Super "O track causing grooving more so than regular track is a myth.
A very interesting and well considered response! Likely also worth considering are the principles of physics that demonstrate why a sharp object such as a sharp steak knife cuts better (or with less force) than a duller object, such as a duller table knife.
As stated in Wikipedia: "Cutting is a compressive and shearing phenomenon, and occurs only when the total stress generated by the cutting implement exceeds the ultimate strength of the material of the object being cut....The stress generated by a cutting implement is directly proportional to the force with which it is applied, and inversely proportional to the area of contact." Hence, the smaller the area (i.e., the sharper the cutting implement), the less force is needed to cut something."
I suspect the "sharper" copper center blade imbedded in Super-O track actually applied (or applies) more of a cutting force to the softer Postwar rollers than did the rounded center rails of the O Gauge track that had previously been in almost universal use.
I do know that the rollers of my Postwar GG-1 had grooves in the center of the rollers, precisely in the area where the rollers contacted the comparatively "sharper" center rails. Those grooves are on that GG-1 today.
