Park Tool's article on headset servicing states the following (emphasis mine):
... If the headset is using bearing retainers, check the orientation of the retainers before installing. Inspect the metal cage that retains the ball bearings. The cage traps each ball with a hook. Look for the open side of the ball retaining hook. This open side of the cage should face the cone shaped race, not the cup shaped race. ...
-Park Tools, Threadless Headset Service, Feb 2023, https://www.parktool.com/en-us/blog/repair-help/threadless-headset-service
I'm sure that Park Tool's description is obvious to more experienced minds, but I find it a bit confusing.
I feel Park Tool's article changes subject between two sentences. They go from talking about the ball retaining hook
to talking about the cage
, and I'm not entirely clear what they're attempting to describe as the "open" side. See here a view of one side of my ball bearing retaining cage I've labeled "side 1":
And see here the other side of the cage I've labeled "side 2":
Although it seems I could just as easily use loose bearings or go through trial and error...
... It is also possible to replace retainer ball bearing with loose bearings. ...
... If in doubt, install the cage, and place the race inside and turn. If the cage is correct, it will feel smooth. ...
... I was hoping to understand the terminology here. Which is the "open" side of the retention cage in this case? Is there perhaps another way to describe which side is open vs not open to help less-experienced people like me?