Brother Cycles Kepler Frames - Blue Metallic

Brother Cycles Kepler is the foundation for a really good gravel or road bike. Classically handsome steel tubing and geometry that works just as well on asphalt as on gravel mean the frame can become anything from a fast commuter to a more relaxed road bike or a dedicated gravel bike. It is this versatility that has made Kepler one of Brothers’ longest-running models.

The latest version has received several thoughtful updates without Brother changing the core concept. The new lugged steel fork has internal dynamo cable routing and three mounting points on each fork leg. The frame has internal rear-brake cable routing, an integrated seatpost clamp, a third bottle-cage mount beneath the downtube, and Brothers’ Oak Leaf emblem in metal on the head tube.

The frame is built from double-butted 4130 chromoly and ED-treated beneath the paint for better protection against corrosion. Kepler can be built with 700C wheels and tyres up to 45 mm, or 650B with tyres up to 48 mm. This lets you choose faster tyres for asphalt and fine gravel roads, or more volume when comfort and grip matter more.

Kepler is also designed to carry gear on the bike. There are mounts for racks and mudguards front and rear, three bottle-cage positions on the frame, and three mounting points on each fork leg. Thru-axles and flat-mount brakes provide modern, readily available standards, while the threaded 68 mm bottom-bracket shell keeps the build itself simple.

Compared with Brother Mehteh, Kepler is the more road-oriented option. You get less tyre clearance and a steel fork instead of carbon, but also a frame with a more classic look and a natural place somewhere between road, gravel, and everyday riding. The Blue Metallic paint also does a lot for the overall impression – dark and fairly understated from a distance, but with a distinct metallic finish when the light catches it.

Quick Specs

• Model: Brother Cycles Kepler
• Type: Steel frameset for gravel and road
• Colour: Blue Metallic
• Frame: 4130 chromoly, double-butted main triangle, ED-treated
• Fork: Lugged 4130 chromoly fork
• Sizes: 50, 52, 54, 56, 58 and 60 cm
• Wheels: 700C or 650B
• Maximum tyre width: 700 × 45 mm or 650B × 48 mm
• Rear axle: 12 × 142 mm thru-axle, included
• Front axle: 12 × 100 mm thru-axle, included
• Brakes: Flat mount, maximum 160 mm brake rotor
• Headset: 1 1/8" threadless, not included
• Seatpost: 27.2 mm
• Bottom-bracket shell: 68 mm, ISO threaded
• Front-derailleur clamp: 28.6 mm
• Maximum chainring: 48T single, 50/34T double or 52/39/30T triple
• Bottle-cage mounts: 3 sets
• Fork mounts: Three mounting points per fork leg
• Mounts: Racks and mudguards front and rear
• Dynamo cable: Internal routing through the fork
• Frame weight: Approximately 2.25 kg in size 56 cm
• Fork weight: Approximately 1.2 kg with uncut steerer tube