| Standard: | Threading | Adjustable (left) cup direction | Fixed (right) cup direction | Shell Width | Applications/Notes |
|---|---|---|---|---|---|
| British I.S.O. | 1.370" X 24 tpi 1.375" X 24 tpi | right | left | Standard 68 mm O.S. 73 mm | The overwhelming majority of bicycles in current production. British and I.S.O. are interchangeable. |
| ISIS Overdrive | 48 x 1.5 mm | right | left | 68mm 100 mm | New proposed standard oversized system. |
| Italian | 36 mm X 24 tpi | right | right (wrong!) | 70 mm | Italian and some high-end French bicycles. Prone to problems due to the right threaded fixed cup, which tends to unscrew itself in use. |
| French | 35 mm X 1mm (25.4 tpi) | right | right (wrong!) | 68 mm | Obsolete, used on older French bicycles. Prone to problems due to the right threaded fixed cup, which tends to unscrew itself in use. |
| Swiss | 35 mm X 1mm (25.4 tpi) | right | left | 68 mm | Same thread as French, but fixed cup is left threaded for reliability. |
| Raleigh | 1 3/8" X 26 tpi | right | left | 71mm 76 mm | Older British-made Raleighs, especially 3 speeds. |
| O.P.C. Ashtabula | Male threads on crank 24 tpi (most) 28 tpi (Schwinn, Mongoose) | 68 mm (2.68") wide 51.3 mm (2.02") i.d. (approximate) | Older U.S. bikes, BMX, Juvenile bikes, Department store bikes. 24 tpi cranks use #66 retainers, with 10 5/16" balls. 28 tpi cranks use #64 retainers, with 9 5/16" balls. Note: Some higher quality(mostly BMX) bikes used Tange 24 tpi bottom brackets with #64 retainers. |
| Bottom Bracket Shell Threading (Below) |
BritishI.S.O. 1.37/1.375" x 24 tpi CUPS R-L (34.8/34.9 x 1.06 mm) | Italian 36 mm X 24 tpi CUPS R-R (1.417" x 1.06 mm) | French 35 mm X 1mm CUPS R-R (1.378 x 25.4 tpi) | Swiss 35 mm X 1mm CUPS R-L (1.378 x 25.4 tpi) | Raleigh 1 3/8" X 26 tpi CUPS R-L (34.9 x 1.06 mm) |
|---|---|---|---|---|---|
| British/I.S.O. 1.37/1.375" x 24 tpi (34.8/34.9 x 1.06 mm) | Made to Fit | 36 mm Cup diameter is too large, thread won't even start. | Cup diameter is slightly too large, usually won't start. Right (fixed) up threaded in the opposite direction. |
Cup diameter is slightly too large, usually won't start. | Diameter matches, but thread pitch does not. Will bind after only a few threads are engaged. |
| Italian 36 mm X 24 tpi (1.417" x 1.06 mm) | British/I.S.O. cups fall through | Made to Fit | Italian shells are larger diameter, all other size cups fall right through, threads will not engage. | ||
| French 35 mm X 1mm (1.378 x 25.4 tpi) | 35 mm = 1.378". Shell is slightly larger, thread pitch slightly finer. Left side may seem to fit, but will be loose. |
36 mm Cup diameter is too large, thread won't even start. | Made to Fit | Left (adjustable) side is interchangeable. Right (fixed) side is threaded in the opposite direction, won't fit. |
35 mm = 1.378". Shell is slightly larger, thread pitch slightly coarser. Left side may seem to fit, but will be loose. |
| Swiss 35 mm X 1mm R (1.378 x 25.4 tpi) | 35 mm = 1.378". Shell is slightly larger, thread pitch slightly finer. May seem to fit, but will be loose. | 36 mm Cup diameter is too large, thread won't even start. | Left (adjustable) side is interchangeable. Right (fixed) side is threaded in the opposite direction, won't fit. |
Made to Fit | 35 mm = 1.378". Shell is slightly larger, thread pitch slightly coarser. May seem to fit, but will be loose. |
| Raleigh 1 3/8" X 26 tpi (34.9 x 1.06 mm) | Diameter matches, but thread pitch does not. Will bind after only a few threads are engaged. |
36 mm Cup diameter is too large, thread won't even start. | Cup diameter is slightly too large, usually won't start. Right (fixed) up threaded in the opposite direction. |
Cup diameter is slightly too large, usually won't start. | Made to Fit |
| Application | Dimension | Notes |
|---|---|---|
| Road Double | 43.5 | Shimano spec, measured to the midpoint between the rings. with typical 5 mm chainring spacing, this puts the inner at 41 mm, the outer at 46 mm. |
| Road Triple | 45 | Shimano spec, measured to the middle ring. |
| MTB Triple | 47.5-50 mm | Shimano spec, measured to the middle ring. 47.5 preferred, but for frames with oversized seat tubes, the longer dimension may be needed, because the fat tube places the derailer mechanism farther to the right. |
| Track/Coaster Brake Traditional One-Speed Most internal gear hubs | 40.5-42 mm | Older bikes with 110 spacing would be on the smaller end of this range Newer bikes with 120 mm spacing normally use 42 mm |
| Singlespeed MTB | 52 mm | Wider chainline need for chainstay clearance on MTBs. This is close to the chainline of the outer ring of a typical MTB triple |
| Singlespeed MTB Alternate | 47.5 mm | White Industries ENO hubs use this chainline, which lines up with the middle position of a typical MTB triple. It's also fairly close to the outer position of a typical "road" double. |
| Rohloff Speedhub | 54 mm (58 mm w/13 tooth) | |
| Freeride and Downhill | 55 mm | Newer Freeride and Downhill bikes with 150 mm spacing |
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.