The Original CBR cranks were nicknamed "Dog Bones" and came out in late 1981/ early 1982. Cook Bros did not make their own spyder at the time so most of the BMX'rs used a steel spyder made by Tange ( I think). So once the klunker fad started, Phil Wood made a CNC Milled aluminum spyder to fit the cranks and that was the "top shelf" set up. Craig Cook made a few prototypes spyders to fit triple TA rings but they were VERY rare (like maybe a handful of them). Then in early 1983 when the new owner of CBR took over, he designed, programed, and milled their own spyders both for single rings and triple Mt. Bike rings (though very rare at that time). Before the new owner took over, CBR had bought a small CNC machine... But no one in the company knew how to program or run it due to Craig Cook parting ways from his brother (in disgust).
Then 2 or 3 years later the RSR was developed (named after the classic Porsche RSR race cars with Porsche's permission). The RSR had a smaller pedal ball, with slots running down their back sides and one of the spyder arms behind the crank arm.
I'll continue this definition of the different CBR crank arms when I have some spare time.
