WikiPedalia is not endorsed or affiliated with the Wikimedia Foundation.
Bead Seat Diameter
From WikiPedalia
The Bead Seat Diameter (B.S.D.) is the crucial dimension that determines whether a particular tire can fit onto a particular rim. It specifically refers to the "shelf"-like area inside the rim where the tire's bead sits.
The Bead Seat Diameter is the fundamental dimension used in the ISO/E.T.R.T.O. system of tire and rim sizing. This is the great virtue of that system, compared to all of the older systems that referred to the tire's outside diameter, with no specific reference to rim diameter or to the rim/tire interface.
