| Article Index |
|---|
| 5. Cup Threads |
| Thread Direction |
| All Pages |
Page 1 of 2
BB - common acronym for Bottom Bracket.
There are a few thread pitches and threading directions but they are virtually all standardized now at British ISO.
WORKSHOP TIP: You may come across Italian road bikes with an Italian threaded BB or an old Raleigh 3 Speed with a 26 tpi BB but generally the standard is ISO.
| Standard | Threading | Non-drive side direction | Drive side direction | Use |
| British ISO | 1.370" X 24 | left hand side | right hand side | Most bikes in production have this threading |
| Itailian | 36mm X 24 tpi | right hand thread | left hand thread | Italian Road Bikes (has 70mm shell) |
| Raliegh | 1 3/8" X 26 tpi | right hand thread | left hand thread | Old Raleighsize Mostly 3 Speeds |
