Originally Posted by
Koyote
According to
this chart on their website, Tufo doesn't even recommend using their 44mm tires on 19mm rims...so it seems unlikely that they are using that rim size when stating their tire widths. The chart also indicates that a 19mm is the
smallest size they recommend with their 40mm tires -- which strongly suggests that they are not using that rim ID for determining the widths of their 40mm tires, either.
Again, it doesn't matter because you don't know. Email them and ask, get some primary source info you can be proud to share.
There is no assumption that we should mentally average the recommend rim width to determine what seems likely. It is as likely that the 40-622 Thundero was designed for a measuring rim of i19 as it is that it was designed for a measuring rim of i/21/i23/i25.
