Rims
ISO 5775-2 defines designations for bicycle rims. It distinguishes between
- Straight-side (SS) rims
- Crochet-type (C) rims
- Hooked-bead (HB) rims
Rims are designated by their nominal rim diameter and their nominal width, separated by a cross (×). Both are measured in millimeters. The rim type codes SS or HB precede the rim designation, whereas code C is appended to the nominal width. Examples:
- SS 400×20, HB 422×25, 620×13C
The nominal width of a rim is the inner width between the straight sides or beads as one can easily measure it with a caliper (see the standard for drawings and exact measurement procedures).
The standard widths of straight-side rims are:
- 18, 20, 22, 24, 27, 30.5
The standard widths of crochet-type rims are:
- 13C, 15C, 16C, 17C, 19C, 21C, 23C, 25C
The standard widths of hooked-bead rims are:
- 20, 25, 27
The standard diameters of straight-side and crochet-type rims are:
- 194, 203, 222, 239, 248, 251, 279, 288, 298, 305, 317, 330, 337, 340, 349, 355, 357, 369, 381, 387, 390, 400, 406, 419, 428, 432, 438, 440, 451, 484, 489, 490, 498, 501, 507, 520, 531, 534, 540, 541, 547, 559, 565, 571, 584, 590, 597, 609, 622, 630, 635, 642
The standard diameters of hooked-bead rims are:
- 270, 321, 372, 422, 459, 473, 510, 524, 560, 575, 611
Read more about this topic: ISO 5775