Vostok Titanium Rear Triangle


Vostok Rear Triangle replaces the original Brompton bicycle rear frame assembly. It allows hubs like Rohloff Speedhub, Shimano Alfine and the like to be fitted with or without the disk brake. With our optional derailleur hanger, a lightweight cassette setup is possible. The Triangle plays well with Brompton's design: the bicycle folds and rolls as expected.

Vostok Triangle left
Vostok Triangle right


Titanium alloy PT-7M*
0.5 kg
OLD Spacing
135 mm
Brake mounts
IS Disk and standard caliper
Rohloff TS OEM
*GOST 19807-91
Superior to Grade-9 alloy
Vostok Rohloff dropout

Hub compatibility

O.L.D. spacing is 135 mm. Dropouts were designed with a Rohloff OEM Speedhub in mind. Fit a Shimano Alfine/Nexus like you would on a regular bike. In fact, go with any standard O.L.D. hub. For cassette setups, any number of sprockets is permissable as long as the lowest sprocket is 36T or less and the highest sprocket is 12T or less. If a Shimano Internal hub is installed along with our chain tensioner, 7L/R black/grey anti-rotation washers must be used.


The Vostok triangle has IS disk mounts and a Brompton caliper brake mount. The disk brake rotor's diameter should be 160 mm. Install either a mechanical or a hydraulic brake. Use an appropriate Post Mount adaptor if needed.


Standard rollers and Eazy wheels will fit the triangle and so will a standard suspension block, mudguard and rear rack. The Brompton pump, unfortunately, cannot be fitted due to the specific geometry of the chainstays.

Now on Indiegogo

Consider adding one of both to your kit:

Vostok Chain Tensioner for the Brompton bicycle
Vostok Derailleur Hanger for the Brompton bicycle