My thought on this (not official) came when this feature first started. In the very beginning of Trackmaster II rolling stock wheels did not have the teeth and what was happening when running the trains through all the hoops, jumps and circus stunts those early sets had the trailing units were not 'tracking' behind the engines very well and would easily derail or tip when performing. This was probably due to their size and weight being a fraction of what we are use to. I think I remember seeing this in early videos. Introducing the teeth on the wheels of rolling stock and coaches alleviated is wandering and seemed to keep following the engine very nicely. I think the only ones that had teeth early on were those that performed some type movement or action within.
A relatively similar thing happens with Plarail/Tomy/Early Trackmaster can be seen when going downhill on Tomy tracks where the cars want to roll down faster than the engine. I always disliked filming trains going downhill because of this.
All of this might have been what was being referred to as "traction" with the geared wheels. But unofficial thought was Trackmaster had to come up with a fix for the derails and the flopping around after the release of Trackmaster II.
A relatively similar thing happens with Plarail/Tomy/Early Trackmaster can be seen when going downhill on Tomy tracks where the cars want to roll down faster than the engine. I always disliked filming trains going downhill because of this.
All of this might have been what was being referred to as "traction" with the geared wheels. But unofficial thought was Trackmaster had to come up with a fix for the derails and the flopping around after the release of Trackmaster II.
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