Just a perfectly designed, simple, steel frame mountain bike, the perfect bikepacker, without sacrificing fun on the trail. We have ridden this bike down alpine downhill black runs, bikepacked in the New Forest, and used everyday as a comfortable offroad cruiser. The Big Bro is a classic.
Our all purpose, tough as nails 29er/27.5+ adventure frame; designed to take you well off the beaten track and beyond. Whether you’re running a lightweight bikepacking setup, stripped back to thrash some forest trails or even front and rear panniers for a ’round-the-world’ tour the Big Bro can handle it.
The frame is made out of tough 4130 double butted cro-mo tubing and comes with a 100mm suspension corrected fork, both with corrosion resistant ED coating applied. There’s clearance for big 29 x 2.4″ tyres or up to 3 inch tyres if you’d prefer to go 27.5+. It features stealth dropper routing, rack mounts, bottle mounts on the seat tube, down tube and under the down tube for an extra bottle or storage. The forks also feature triple bottle mounts to fit further bottle cages or Anything Cages. S-bend chainstays with replaceable alloy thru axle sliding dropouts allow for geared or singlespeed setups.
Like all Brother products the Big Bro has been rigorously tested out in the real world – we took prototypes across the South Downs, through Snowdonia National Park and up to the Scottish Highlands. The Big Bro has since completed two of the worlds toughest bikepacking endurance races – the 4,418km Tour Divide from Canada to Mexico and the 1,710km Silk Road Mountain Race in Kyrgyzstan.
Tubing: – 4130 Chromoly steel – double-butted main triangle, ED coated
Brake compatibility; 51mm IS disc brake mount, 180mm max rotor size
Dropouts: 12x142mm thru axle (included)
Seat post diameter: 30.9mm
Seat clamp diameter: 33.1mm (included)
Headset: 44mm, SHIS ZS44/28.6 upper, EC44/40 lower (not included)
Front derailleur clamp diameter: 34.9 mm high direct-mount (adapter available separately)
Bottom bracket shell: 73mm bottom bracket, ISO threaded
Maximum tyre clearance: 29″ x 2.4″, 27.5″ x 3.0″ (note: not all drivetrains allow for these maximum tyre clearances)
Fork : 4130 Chromoly tapered unicrown fork, ED coated. 15x100mm thru axle (included)
Full-length cable housing guides for derailleurs and brakes
3 sets bottle cage mounts on all sizes
Chainring clearance: up to 48-36-26t triple, 42-28t double, 38t single
Weight: medium (18″) frame 2.6kg, fork (260mm steerer) 1.25kg
Tested to ISO 4210 MTB standard