Hey Groovychick...
I put new shoes on my truck and went to the new download-able manual to find out how to change the tire size and found a little bitty typo (well, actually the omission of one numeral:
On page 15, step 3, the equation reads:
27.5 + 431.8. It should read:
427.5 + 431.8.
Thanks for all you do!
"Glock"