The Bendix coaster-brake is a complex machine. It uses “brake shoe keys”, which would later be replaced with integrated keys on other companies models. It also used a different type of spring (labeled retarder spring), which is somewhat similar to the retention spring in Joy-tech style cassette hubs. This provides fairly uniform tension and resistance. Thirdly, it used a very short driver and clutch. This lowered weight and freed up some room in the hub. additionally, this helped to prevent twisted drivers. However, having such a short driver reduces the amount of slack available, so this hub is not the most ideal to convert to a freecoaster. And lastly, The driver was available with three different cog retention systems: The traditional 3-lug system (which suffered from never being tight, a splined system (similar to Shimano style cogs) and a thread on system this allowed much more strength in the cog system. Sorry for the large picture, but it helps to visualize better.