Brother Cycles Kepler 2026 Frameset
The Brother Cycles Kepler is a steel frameset for commuting, gravel rides and loaded touring. Its double-butted 4130 chromoly frame is paired with a lugged steel fork, giving you a platform that can be built for everyday transport or longer journeys. The 2026 version adds hand-drawn graphics while retaining the established Kepler geometry.
Choose 700c wheels with tyres up to 45mm or a 650b setup with tyres up to 48mm. Rack and mudguard fittings, three bottle positions and triple mounts on the fork make room for the equipment a longer trip needs. Internal rear-brake routing and a brazed seat collar keep the frame layout tidy, while an ED coating beneath the paint helps protect the steel against corrosion.
This listing is for the frameset. Complete-bike photographs show possible builds; wheels, drivetrain and finishing components are not included. Match your build to the axle, brake, headset and bottom-bracket specifications below.
Technical specifications
- Tubing: 4130 Chromoly steel - double-butted main triangle, ED coated
- Brake compatibility: flat mount, 160mm max rotor size
- Rear Dropouts: 12x142mm TA (included)
- Seat post diameter: 27.2mm
- Headset: 1 1/8˝ threadless steerer/headset (not included)
- Front derailleur clamp diameter: 28.6 mm
- Chainring clearance: up to 52-39-30t triple, 50-34t double, 48t single
- Bottom bracket shell: 68mm bottom bracket - ISO threaded
- Tyre clearance: up to 700x45c or 650x48c
- Fork: 4130 Chromoly lugged fork - 300mm steerer, 12x100mm TA (included)
- Frame weight: 56cm = 2.25kg
- Fork (with uncut steerer): 1.2kg
- Tested to ISO 4210 standard
Frame geometry
| Frame Size (C-TT) | 50cm | 52cm | 54cm | 56cm | 58cm | 60cm |
|---|---|---|---|---|---|---|
| Seat Tube (C-C) | 485mm | 505mm | 525mm | 545mm | 565mm | 585mm |
| Top Tube | 520mm | 530mm | 545mm | 560mm | 575mm | 595mm |
| Head Tube | 95mm | 95mm | 105mm | 124mm | 142mm | 161mm |
| Head Angle | 71 | 71 | 71.5 | 72 | 72 | 72 |
| Seat Angle | 74.5 | 74 | 73.5 | 73 | 72.5 | 72 |
| BB Drop | 70mm | 70mm | 70mm | 70mm | 70mm | 70mm |
| Chainstay | 430mm | 430mm | 430mm | 435mm | 435mm | 435mm |
| Fork Length (A-C) | 400mm | 400mm | 400mm | 400mm | 400mm | 400mm |
| Fork Rake | 50mm | 50mm | 45mm | 45mm | 45mm | 45mm |
| Stack | 530mm | 530mm | 543mm | 562mm | 580mm | 598mm |
| Reach | 372mm | 378mm | 384mm | 387mm | 392mm | 401mm |
| Wheelbase | 1009mm | 1014mm | 1014mm | 1025mm | 1035mm | 1049mm |
Available options
- Frame Size: 50cm, 52cm, 54cm, 56cm, 58cm, 60cm
- Colour: Blue Metallic, Green Metallic
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.
Frequently Asked Questions
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Please get in touch with a member of the team either by phone (01313745324) or email ([email protected]) where on of the team will be more than happy to help.
ProjektRide Bike Shop Edinburgh
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If the item is showing in stock, we aim to post the product within 24 hours. Please allow 5 working days to receive the item.
Postage is free on orders over £50. Orders under £50, our postage charge is £3.99.
We also have a physical store, if you are local please pop in -
ProjektRide Bike Shop Edinburgh