First there was a standard width of rims. Then FRM and No Tubes got wider rims with 21mm inner width. No we have American Classic with 24mm inner width on their lightest wheelset and on their Wide Lightning it’s 29,3mm. Super wide I thought
Then Ibis came with new carbon rims:
Available in 27,5″ and 29″. With 41mm outer width and 35mm inner width.
More info here: Bikerumor