Mountain bike dating
This allowed them to build the bearing into the inside of the pedal thread, eliminating the need for a pedal axle.The purpose of this was to improve the biomechanics of the pedal by placing the bottom of the foot below the pedal axis.The Ultegra name was added as a suffix to 600 when 7-speeds (and the gray paint finish) came in in the early '90s.
For example, to reap the benefits of Hyperglide or Superglide, you need to use one of the specific combinations of sprocket sizes designed to work together.
Pronounced "alfeenay" as in Italian -- Shimano's name for its high-end series of internal-gear hubs and related parts.
There are 8-speed and an 11-speed hubs and a front dynamo hub.
See also the 1973 Shimano Dura-Ace Catalogue on this site.
In the early '80's, Shimano introduced a special crank/pedal set, which used much larger diameter threading where the pedal screwed into the crank.