| Handlebar dimensions | ||||
|---|---|---|---|---|
| Stem Clamp Size | Grip Area Size | Application | ||
| 22.2 mm | 7/8" | 22.2 mm | 7/8" | Steel bars. Mainly BMX, older Mountain bike bars. |
| 23.8 mm | 15/16" | 22.2 mm | 7/8" | Obsolete British size for steel handlebars, common on older 3-speeds. This size was also used for older British steel drop bars. |
| 25 mm | 23.5 mm | Obsolete French size. | ||
| 25.4 mm | 1" | 22.2 mm | 7/8" | Standard I.S.O. size, used on the vast majority of newer bicycles with upright handlebars. This size was formerly common for steel drop bars. |
| 25.4 mm | 1" | 23.8 mm | 15/16" | Standard I.S.O. size, used on most bicycles with drop handlebars. Also used on older British aluminium upright handlebars. |
| 25.8 mm | 23.8 mm | 15/16" | Unofficial in-between size used by some Italian handlebar makers for handlebars designed to be usable in either ISO (25.4) or Italian (26.0) size stems. | |
| 26.0 mm | 23.8 mm | 15/16" | Italian standard for drop bars, other bars made to fit Italian stems and some high-end aftermarket drop bars. This is sometimes incorrectly called "road" size. | |
| 26.4 mm | 23.8 mm | 15/16" | Older Cinelli and Cinelli copies. Cinelli changed over to 26.0 mm in 1998. | |
| 27 mm | 23.8 mm | 15/16" | Titan (obsolete). | |
| 31.8 mm | 1 1/4" | 23.8 mm | 15/16" | Road oversized. |
This page is intended as a quick reference primarily for the benefit of folks in the bicycle business. Feel free to print it out, but please don't reproduce it without proper credit and linkage.