Brother Cycles Stroma Electric Blue - Frames

Brother Cycles Stroma is a frameset for anyone who wants to build a fast road bike that does not have to stay at home just because the weather or road surface gets worse. Stroma is designed for year-round cycling and sits somewhere between road, all-road and fast gravel. Our advice is much the same as before: ignore the weather gods and ride anyway.

The geometry is clearly road-oriented, but Stroma offers more versatility than a traditional race frame. There is clearance for tyres up to 700 × 38 mm, or 32 mm with full-length mudguards, giving you considerably more freedom when the asphalt gets rough or the ride continues onto gravel. Mounts for mudguards and a rear rack also make the frame work very well as a fast year-round bike, commuter or long-distance road bike.

The frame has a heat-treated Reynolds 725 main triangle and a specially formed Reynolds 520/500 rear triangle. Up front is Brother's carbon fork with a 12 × 100 mm thru axle, mudguard mounts and internal dynamo cable routing. The combination of a steel frame and carbon fork gives Stroma the blend of compliance and direct feel that suits a fast bike for longer days in the saddle.

At the rear, there is a 12 × 142 mm thru axle and flat mount disc brakes with up to 160 mm rotors. The frame has two bottle-cage positions, mounts for a rear rack and mudguards, plus cable ports for Di2 that can also be used for internal routing to a rear dynamo light. The threaded 68 mm bottom bracket shell and standard 27.2 mm seatpost keep several of the key standards straightforward.

Compared with the Brother Kepler, Stroma is more clearly road-oriented, with less tyre clearance, a lighter carbon fork and a more focused feel for asphalt and faster gravel. The Electric Blue version combines the vivid blue paint with white sections across the rear triangle, top tube and fork – a fairly classic race look on a frame built for considerably more days of the year than a traditional road bike.

Quick Specs

• Model: Brother Cycles Stroma
• Type: Steel frameset for road, all-road and fast gravel
• Colour: Electric Blue
• Frame: Reynolds 725, heat-treated and double-butted main triangle, ED-treated
• Rear triangle: Reynolds 520/500
• Fork: Brother monocoque carbon fork with tapered steerer
• Sizes: X-Small, Small, Medium, Large and X-Large
• Wheels: 700C
• Maximum tyre width: 700 × 38 mm
• Maximum tyre width with mudguards: 700 × 32 mm
• Rear axle: 12 × 142 mm thru axle, included
• Front axle: 12 × 100 mm thru axle, included
• Brakes: Flat mount, maximum 160 mm rotor
• Headset: ZS44/28.6 upper / EC44/40 lower, not included
• Seatpost: 27.2 mm
• Seatpost clamp: 30 mm, included
• Bottom bracket shell: 68 mm, ISO threaded
• Front derailleur clamp: 28.6 mm
• Maximum chainring: 50T single or 53/39T double
• Bottle-cage mounts: 2 sets
• Mounts: Rear rack and mudguards, fork mudguard mounts
• Dynamo cable: Internal routing through the fork
• Di2: Cable ports in the frame
• Frame weight: Approximately 1.97 kg in size Medium
• Fork weight: Approximately 500 g with uncut steerer