What is the largest replacement tire available?

[98 SNAKE EATER]

I'm nearing 1000 miles on my X3 Pro and just picked up another puncture in my rear tire

Slime sealed it up just fine, but I figure it may be time to start looking into replacement tires

What is the largest size I can fit without rubbing?

 

[98 SNAKE EATER]

So I'm looking at my stock rear tire (26 x 4) and there's about 3/4 clearance from the chain in low gear

If I were to get a 26 x 5 tire, I'm guessing it would only be about 1/2" wider (per side), so I should still have about ~1/4" clearance from the chain

Has anyone else here gone this big?