Oh, interesting. I’ve converted a 44mm headset lower bearing from 1 & 1/8 to 1.5", but didn’t realize that similar options existed for the top. Good to know.
I don’t really understand why they decided to do 1.25". If 1 &1/8 to 1.5" tapered is good enough for mountain bikes, then surely it is good enough for an adventure bike.
Of course, the youtube reviewer could have got it wrong. Maybe they thought 1/8" = 0.25" …