This is the magic number for me, 26 x 2.4. Manufacturer charts show my 21mm ID rim is approved for a 2.4 tire. 2.4 is also the largest which will fit my cross country frame, front and back. My good fortune was to find a Panaracer Swoop AllTrail non-tubeless which was a true 2.4. Light enough for cross country, and sealing well on a TLR rim. So I bought another, it was labeled 2.4 but was significantly smaller, like a 2.2. And the Continental Mountain King protection 26 x 2.4 I just bought is also smaller than the original AllTrail, again closer to 2.2. Who has a truly large 2.4? It's too expensive buying these things remote without knowing what the actual size is, and the few local shops left here do not carry them. Thank you for your reply!