Brother Cycles Stroma Rubble - Frames

Brother Cycles Stroma is a frameset for anyone who wants a fast road bike that works all year round. It has clearly defined road geometry, but increased tyre clearance, disc brakes, and mounts for mudguards and a rack mean the Stroma can handle much more than fine summer days on perfect asphalt. Our advice is much the same as before: ignore the weather gods and ride anyway.

The frame is built with a heat-treated Reynolds 725 main triangle and a formed Reynolds 520/500 rear triangle. Up front is a Brothers carbon fork with a 12 × 100 mm thru-axle, mudguard mounts, and internal dynamo cable routing. The combination gives the Stroma the fast and direct feel of a road bike, but with room to build a bike that is actually used throughout the year.

Tyre clearance is up to 700 × 38 mm, or 32 mm with full-length mudguards. That is enough to move from fast road tyres to more comfort and grip on poor asphalt and lighter gravel. There are mounts for both a rack and mudguards at the rear, and the frame has two bottle cage positions. The Di2 ports can also be used for internal cable routing to a rear dynamo light.

The Stroma is not Brothers’ gravel frame with large tyres and plenty of load-carrying options – Kepler, and Mehteh above all, are closer to that description. The Stroma is the more road-oriented bike: fast, responsive, and built for anyone who still wants the feel of a proper road bike but does not want rain, poor roads, or a long winter to decide when it can be used.

The Rubble version combines a sand-coloured frame with white sections on the front and rear triangles and vivid pink Brother decals. A rather unusual look on an otherwise classically proportioned steel frame.

Quick Specs

• Model: Brother Cycles Stroma
• Type: Frameset for road, all-road, and fast gravel
• Colour: Rubble
• Frame: Reynolds 725, heat-treated and butted main triangle, ED-treated
• Rear triangle: Reynolds 520/500
• Fork: Brother monocoque carbon fork
• 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: 53/39T double
• Bottle cage mounts: 2 sets
• Mounts: Rear rack and mudguard mounts, 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 tube