Nikolaev - a Cost-Conscious Tour Build

Rear TriangleChain Tensioner Mk2Fork Hook


This kit will allow you to build an internal hub Brompton, be it Shimano Alfine or Rohloff (or any other internal hub), with either a full set of rim brakes or a rear disk/front rim brake combo.

Compatibility and Build Considerations

Stock Alfine 11 sprockets will clear the stay as well as Rohloff sprockets up to 18 teeth (although, there is usually no practical need for such gearing). Bolt-on axle vs QR is entirely your choice. Please use a tandem (142mm) skewer. The Vostok Chain Tensioner will consume the additional lenghth.

Get in Touch

Feel free to message us with any questions about the components and your future build.

Message us

Titanium Finish Options

Blasted matte finish, standard for all Brompton parts.

$779 as a kit

$816 if bought separately


Hand polished titanium, a mirror-like surface resembling chrome.

$0 as a kit

$0 if bought separately


Titanium nitride coating, commonly found on motorcycle forks, drill bits and gun components.

$0 as a kit

$0 if bought separately


Frame Extremities

Rear Triangle

Titanium alloy PT-7M
0.54 kg
O.L.D. spacing
135 mm
Brake mounts
IS Disk and standard caliper
Rohloff TS OEM as well as Shimano non-turn-specific
GOST 19807-91
Superior to Grade-9 alloy

Vostok Rear Triangle replaces the original Brompton bicycle rear frame assembly. It allows hubs like Rohloff Speedhub, Shimano Alfine or any other standard 135mm wide hub to be fitted with or without the disk brake.

The Triangle plays well with Brompton's design: the bicycle folds and rolls as expected. May be paired with a stock front fork as well as the Vostok Fork. When paired with a stock fork, the folding width of the bike does not change considerably.

Considerations: the dropouts will not allow crank arms to rotate 360 degrees when a bike's rear end is folded. Double chainsets may be a problematic fit be it a stock rear triangle or our custom one: choose your BB spacers wisely. Disk brake caliper space is tight and may not fit certain cheaper brands of cable-actuated calipers. There are no issues fitting hydraulic calipers of any kind.

The Triangle is compatible with a standard Brompton rear rack. We feel that our Rear Mini Rack for the Vostok Rear Triangle is the cleanest choice however.

Kit Addons

Chain Tensioner Mk2

Aluminium and Titanium
0.11 kg
Jockey Wheels
Aluminium 11 Deep Tooth Steel Bearings
Chain Line
43 to 58

A lighter modification of the original Vostok Chain Tensioner. Titanium jockey wheel axles, aluminium arms and jockey wheels. This chain tensioner interfaces natively with the Vostok Triangle and includes a recess for a Shimano anti-rotation washer.

The idea behind variable chain line is simple: by moving the jockey wheels across the axles, you achieve perfect chain line no matter the hub or sprocket or cranks you install on your Brompton.

Fork Hook

0.01 kg

The Fork Hook comes included with every fork purchased separately and with every kit. If you are purchasing a Rear Triangle separately, makes sense to add the hook to your order. With the rear-only conversion, the hook is optional, but recommended for a rear derailleur build. A rear derailleur, being wide and bulky, might not permit the full fold with the stock plastic hook. The Vostok hook permits modulating the gap between the fork and the rear triangle.

Consider Adding

Rear Mini Rack - Vostok Triangle

The Rear Mini Rack (Vostok Geometry) provides a clean and lightweight alternative to the stock Brompton rack when paired with the Vostok Triangle. The stays of the rack are welded to a 135mm O.L.D. standard. Available in both raw and satin finish.



Front Cargo Rack

A front Brompton rack done right, with a wide base and vertical railings to attach your non-Brompton briefcase of duffel. Will sit firmly on the plastic or titanium carrier block.



Caroline Alexander

Caroline Alexander (born 3 March 1968) is a cross country mountain biker and road cyclist born in Barrow in Furness, Lancashire.

Katie Archibald

Katie Archibald, MBE (born 12 March 1994) is a Scottish racing cyclist, who currently rides on the track for Great Britain and the Scottish Cycling team.

A member of the Great Britain 2016 Olympic champion team in women's team pursuit, she is a former champion in the same event at both the World (2014) and European (2013, 2014 and 2015) championships. Individually, Archibald has been European champion in the elimination race in 2015, twice in the omnium in 2016 and 2017 and a four time European champion in the individual pursuit between 2014 and 2017.

In 2017 she secured her first individual global title, winning the Omnium at the 2017 UCI Track Cycling World Championships and won a third world championship the following year when partnering Emily Nelson to win the Madison at the 2018 UCI Track Cycling World Championships.