Brother Cycles Stroma Frameset - 2026

The Stroma is our versatile, year-round road bike, designed for the ever-changing weather and road surfaces of the UK and beyond. All-road, fast gravel, endurance – however you want to classify it, the Stroma is fast, responsive and comfortable over distance, no matter how rough the road gets.

The Stroma lives up to its namesake; a remote island off the north east coast of Scotland, battered by ferocious weather and near-impenetrable tides.

The frame is built from Reynolds 725 steel – a heat-treated tubing that offers an excellent balance of strength, weight and ride quality, and one we think is particularly well suited to a bike designed to be ridden year-round. Up front, our full-carbon road fork keeps things light and responsive, with internal dynamo routing, further enhancing the Stroma's endurance credentials.

There's clearance for up to 38mm tyres, or 32mm with full mudguards, with fitted eyelets on both the frame and fork.

Other details include thru-axle flat-mount dropouts, replaceable dropout inserts, two bottle cage mounts, rear rack mounts and Di2 routing – which also neatly doubles as internal routing for a rear dynamo light.

Please note: the 'Brother' branding on the downtube is a brighter orange than it appears in the photos above.

Features
Frame tubing: Reynolds 725 heat treated chromoly double-butted main triangle, ED coated. Reynolds 520/500 custom formed rear triangle.
Brake compatibility: flat mount, 160mm max rotor size
Rear Dropouts: 12x142mm TA (included)
Seat post diameter: 27.2mm
Seat clamp diameter: 30mm (included)
Headset: 44mm, ZS44/28.6 upper, EC44/40 lower (not included)
Front derailleur clamp diameter: 28.6mm
Bottom bracket shell: 68mm bottom bracket, ISO threaded
Maximum tyre clearance: up to 700c x 38mm (32mm with mudguards)
Fork: 1.5″ – 1.1/8″ tapered steerer carbon monocoque disc fork, mudguard mounts. 12x100mm TA (included), dynamo routing
2 sets bottle cage mounts on all sizes
Rear rack and mudguard mounts
Di2 cable ports
Chainring clearance: up to 53-39t double, 50t single
Frame weight (medium): 1.97kg
Fork weight (uncut steerer): 0.50kg

Geometry