Originally Posted by
Jeff Wills
A 18-622 tire is 18mm wide when mounted on a "correct" rim that has a bead seat 622mm in diameter. This is a very, very narrow tire, and may be too narrow to work correctly on a Dyad rim.
The 18-622 was the RIM designation, not a tire designation. So, the "18" is the interior width of the rim and this one is a bit wider than the nearly standard 13 mm wide rims used for road tires.