Originally Posted by
Adrianinkc
I was told the change occurred because of a change in a standard on toe overlap that they had to make a change in tire size. Asked about the rear and they said legally speaking allow 6mm around the tire. This is what I got through the chat option on trek.com
6mm is the ISO-4210 standard. That is what you usually will see in print. Yes, there is a difference between "Max tire size" and "what will fit." Shoot, I run a 50mm front tire on a CX bike sometimes, because it fits.
(yes Gus, ISO has a different standard for road bikes)