Brother Cycles Big Bro 2025 Frameset

Tubing 4130 heat-treated Chromoly steel; double-butted main triangle; ED coated.

Brake Compatibility 51 mm IS disc mount; 180 mm max rotor.

Dropouts Boost 12×148 mm thru-axle (included).

Gear Hanger SRAM UDH type; full-mount compatible.

Seatpost Diameter 30.9 mm.

Seat Clamp Diameter 33.1 mm (included).

Headset 44 mm; SHIS ZS44/28.6 upper, EC44/40 lower (not included).

Front Derailleur 34.9 mm clamp, top-pull, or high direct-mount (adapter available separately).

Bottom Bracket Shell 73 mm, ISO threaded.

Maximum Tyre Clearance 29" × 2.6" or 27.5" × 3.0" (note: not all drivetrains allow these clearances).

Fork 4130 Chromoly tapered unicrown; ED coated; 15×110 mm Boost thru-axle (included).

Cable Routing Full-length housing guides for derailleurs and brakes.

Bottle Mounts Three sets on all sizes.

Chainring Clearance 48-36-26T triple, 44-30T double, 38T single.

Weight Frame (medium/18") 2.60 kg; fork (300 mm steerer) 1.37 kg.

Testing ISO 4210 MTB standard.

Are Brother Cycles frames guaranteed?

The frames are fully guaranteed against manufacturing and materials faults or defects for a period of three years from date of purchase. This guarantee does not cover items which are damaged through accident, misuse, wear and tear, neglect or those which have been repaired or altered by any other firm. Paintwork is not covered by this warranty, nor is any damage that happens to you or your other components as a result of any failure of one of our products.

This guarantee is only valid to the original customer and is non-transferable. Brother Cycles reserve the right to an independent opinion on whether the goods qualify for a refund. A dated proof of purchase must be provided before a warranty claim will be considered.