Vostok Vostok Brompton Chain Tensioner


Vostok Chain Tensioner is designed to interface with our rear triangle. It has an adjustable chain line and a strong spring. Supplied with quality pulleys with ceramic bearings.

Vostok Chain Tensioner top
Vostok Chain Tensioner bottom


Aluminium alloy
225 g
Aluminium 13T ceramic bearings
Chain line
46 - 56 mm
Rohloff Sprocket
13T - 18T
Vostok Chain Tensioner installed

Hub compatibility

The chain line can be adjusted from 46 mm to 56 mm by rotating the jockey wheel axle bolts. For Shimano Internal Hubs, use 7L/R black/grey anti-rotation washers for proper cable routing: there is a recess in the chain tensioner to accomodate the anti-rotation washer. For Rohloff, this recess can be ignored completely.

Sprocket Clearance

Our chain tensioner's arms are longer then of a stock Brompton's and will clear stock Alfine/Nexus sprockets and Rohloff sprockets up to 18T. For Shimano, use a sprocket with or without a plastic chainguard.


An axle nut or a quick release skewer can be used to secure the tensioner on the dropout. The tensioner was designed for our custom triangle and fork kit. It may be used with the Vostok Rear Triangle alone, but may not clear the stock fork blades when the bike is folded if used with a Rohloff Speedhub and certain sprockets. Use with Shimano Alfine in such setups is permitted without limitations.

Vostok Derailleur Hanger

If you would like to assemble an ultralight cassette Brompton, consider the derailleur hanger. It will interface perfectly with the Vostok Triangle.