The 2025 Brother Cycles Stroma is a Reynolds 725 steel all-road frameset for regular riding through changing weather and road conditions. It suits an endurance road bike, a practical commuter or a light touring setup, with a full-carbon fork and fittings that support a useful year-round build.

The frame accepts tyres up to 38mm, reducing to 32mm when full mudguards are fitted. The 2025 carbon fork includes internal dynamo routing, while rear rack mounts, two bottle positions and Di2 cable ports add flexibility. Those frame ports can also be used for a rear dynamo-light cable.

Electric Blue and Rubble are the colour options for this model-year listing. The sale price applies to the frameset rather than a complete bicycle. Use the geometry and component specifications below to choose the right size and plan a compatible wheelset, brake system and finishing kit.

Technical specifications

• 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

Frame geometry

Available options

• Frame Size: Large, Medium, Small, X-large, X-small
• Colour: Electric Blue, Rubble

Frame warranty

Brother provides a three-year warranty against manufacturing and material defects for the original purchaser, with proof of purchase required. Paintwork, normal wear, misuse and damage caused by neglect or modification are excluded. Refer to the manufacturer’s full warranty terms for the conditions that apply.