Originally Posted by
ThermionicScott
I think the spacing was more nebulous back then... a 5-speed bike might be 120-124ish mm, 6-speed required a definite bump up to 126ish, and 7-speed freewheels generally require a little bit more than that in practice.
True. The reality of rear OLN is much more complicated than 120 vs. 126. I have seen 120, 121 (which is really 4¾"), 122, 124, 125, 126, 128, and 130 rear OLN with freewheels.
That's because rear OLN width
should be driven by freewheel width. There was no set standard for what width a freewheel "should" measure.