Aaron Crabbwrote a review of Schwalbe Pro One Tire - Tubeless on June 21, 2017
Familiarity: I've used it once or twice and have initial impressions
I wound up with both the 28mm and the 23mm versions of this (I think the 25 wasn't available when I was ordering).
The 28 setup tubeless on a modern rim very well. The 23 I have a tube in for now, but I had no fitting problems or any such jazz.
These are clearly super nice tires from just a stroll around the block.
But what I wanna talk about is the size of these tyres. These things are rather huge. The 28 barely fits in my frame and measures 31mm on my calipers. Literally, its the same size as some Mavic 30's that I have mounted on slightly narrower rims. How does the 23 look? Well...I kid you not, it measures closer to 25mm. Compared to the old faithful Conti GP4000s 25, the ProOne 23 is slightly less voluminous but still sits just as wide.