Sturmey Archer Brompton 12spd 112mm Rear hub
| Hub Data | ||
|---|---|---|
| Manufacturer | Sturmey Archer | |
| Model | Brompton 12spd | |
| Descriptor | ||
| Position | Rear | |
| Axle Type | 13/32" | |
| OLN | 112 mm | |
| Spoke Interface Type | J-Bend | |
| Brake Compatibility | rim brake | |
| Drive Interface | Shimano 1 (SS, <27mm) | |
| Internal Gearing | 3 speed | |
| Dynamo Type | none | |
| Spoke Hole Diameter | 3 mm | |
| Left Flange Diameter | 68 mm | |
| Right Flange Diameter | 68 mm | |
| Left Flange Offset | 19.5 mm | |
| Right Flange Offset | 17 mm | |
| Mid-Flange Offset | -1.3 mm (to the left) | |
| Weight | 0 g | |
| URL | ||
| Metadata | ||
|---|---|---|
| Hub ID | 1726 | |
| Record Status | Public | |
| Created | Jan 29, 2025 5:11pm | |
| Contributed By | Karl | |
This is the 3-speed internally-geared hub used on Brompton folding bikes with the 12-speed drivetrain. Four cogs are mounted on the driver to make 12 gear combinations when used with the three hub ratios. Driver is 16.0mm wide from shouder to bitter end, and uses common lockring threading. The outermost 1.5mm of the splines is reduced to the minor diameter just like a common Shimano freehub body for 11t cog compatibility. The freehub body shoulder is 26.0mm from the locknut/dropout face. The stock cassette is 11,13,15,18 teeth. The center-to-center spacing of the four cogs is approximately 4.5mm. (The bikes come stock with a YBN 10-speed chain)
The internal gear ratios appear to be approximately 1.563 overdrive and 0.640 underdrive. (not super precisely derived!)
This hub was measured while still part of a complete wheel, so don't trust the dimensions to be absolutely precise. The hub shell says "Sturmey Archer" on one side and has the Brompton bike logo on the other side. There is no printed hub model like is done with the BWR and BSR hubs.
The internal gear ratios appear to be approximately 1.563 overdrive and 0.640 underdrive. (not super precisely derived!)
This hub was measured while still part of a complete wheel, so don't trust the dimensions to be absolutely precise. The hub shell says "Sturmey Archer" on one side and has the Brompton bike logo on the other side. There is no printed hub model like is done with the BWR and BSR hubs.