I’ve just got a specific German headset and I have a quick question re: cups
They are very similar but slightly different
One is more rounded where the bearings sit than the other which has less of a curved area.
Is the more rounded one the bottom so it covers the crown race. While the less curved one is covered by the adjustable race?
as per pic below
What are you asking?
The diagram shows how it’s installed. Lower head tube race at the bottom, upper at the top.
That is not a pic of my headset btw
Blakey how do I tell which one is the bottom cup and which is the top cup?
Post a photo of your headset then.
Generally, one cup will foul on the fork crown, that’s the upper cup.
Ok, so what you need to do is this:
Assemble a cup/bearing race/top cone (between bearings and spacer, top line of your photo) and see if the cup/cone touch/foul. If they do, that’s wrong, try the other cup.
If they both clear, try the same process on the fork crown race (installed on the fork) with bearings and a cup and see if one fouls.
If they still both clear, it doesn’t matter which goes where.
^ cheers
I haven’t done that yet but I’m guessing the one on the right is the bottom cup
I thoroughly recommend using head set press for installation… Personally i like to use a hammer but apparently there is a better way…
I havent done it for a while but Im pretty sure the larger head tube cup is the bottom cup of the headset.
You can build a headset press with a long threaded bolt If you can be bothered but I’ve always just used a couple of pieces of wood and a hammer:
Just checked and can confirm the larger one goes on the bottom of the head tube
and they fitted perfectly 
so happy to get the ‘correct’ headset and have it fit without shimming