Brother Cycles Big Bro 2027 Frame Set

The Brother Cycles Big Bro 2027 is a versatile, extremely robust 29er/27.5+ adventure frame, designed for demanding bikepacking tours, off-road adventures and long journeys far off the beaten track. Whether with a lightweight bikepacking setup, fully loaded front and rear racks for a round-the-world trip, or a minimalist setup for fast forest and gravel trails – the Big Bro reliably masters every challenge.

Model 2027

Sizes: S, M, L, XL

New colours for 2027

• Light blue
• Khaki brown

Pre-orders are now open: Delivery date November/December

The photo is for illustrative purposes only; we will upload updated images as soon as we receive them.

The Brother Cycles Big Bro frameset is a versatile adventure frame made from robust 4130 chromoly steel, ideal for bikepacking, round-the-world trips and off-road touring. It accommodates wide tyres (up to 27.5″ x 3.0″ or 29″ x 2.6″), features numerous mounting points for luggage racks and bottle cages, and comes with a sturdy steel fork with Boost thru-axles.

Specifications:

Frame & Fork

• Material: 4130 heat-treated chromoly steel, double-butted, ED-coated (corrosion-resistant)

• Fork: 4130 chromoly, tapered unicrown, 15x110 mm thru-axle (included)

• Weight: Frame (size M/18″) approx. 2.6 kg; fork approx. 1.25–1.37 kg

⚙️ Technical specifications

• Brake mount: 51 mm IS disc mount, max. rotor size 180 mm

• Dropouts: Boost 12x148 mm thru-axle (included), compatible with single-speed or derailleur

• Derailleur hanger: SRAM UDH type, fully mountable

• Seatpost: Ø 30.9 mm

• Seat post clamp: Ø 33.1 mm (included)

• Headset: 44 mm, SHIS ZS44/28.6 top, EC44/40 bottom (not included)

• Front derailleur mount: Ø 34.9 mm, top-pull or high direct mount (adapter available separately)

• Bottom bracket: 73 mm ISO thread

• Tyre clearance: up to 29″ x 2.6″ or 27.5″ x 3.0″

🚵 Intended use

• Perfect for bikepacking adventures, long tours and challenging trails

• Numerous mounting points for bottle cages, luggage racks and panniers

• Compatible with dropper posts (Stealth routing)

• Tried and tested in long-distance races such as the Tour Divide (4,418 km) and the Silk Road Mountain Race (1,710 km)