MIDDLEBURN RO2 ROAD X-TYPE CRANK FOR EXTERNAL BOTTOM BRACKET

Middleburn RO2 X-Type Cranks are precision-engineered for road cyclists who demand strength, stiffness, and lightweight performance. These RO2 bike cranks come complete with a 24mm axle, axle nuts, and all necessary fittings, designed for use with any external bottom bracket using 24mm bearings, as per HollowTech2 standards.

The Middleburn RO2-X-175 crankset (including the SP-RO2-X-94-X2 spider) weighs approximately 568g including all fittings, with a Q-factor of around 153mm, providing optimal pedalling efficiency and comfort. All Middleburn RO2 road bike cranks are fitted with a 24mm axle compatible with HollowTech2-style bottom brackets for a secure and reliable fit.

First developed in 1991, Middleburn cranks have undergone continuous refinement. The RO2 X-Type design is the latest in road bike crank technology, engineered to work with external bottom brackets and push-fit systems (with the appropriate axle). Advanced 3D stress modelling ensures these cranks are among the stiffest yet lightest road bike cranks available.

Crafted from hot forged 7075 T6 aluminium, each crank is CNC machined, hand-polished, anodised, and re-machined with the Middleburn logo, guaranteeing consistent precision and quality across every arm.

The image shows an RO2 crankset built with the SP-RO2-X-94-X2 spider, paired with dedicated 11-speed 46/30 chainrings and stainless-steel bolt set. If you order a spider or UNO chainring with your cranks, we can mount it for you before shipping; just add a note at checkout.

Key Features of Middleburn RO2 Road X-Type Cranks

• Stiff and lightweight aluminium construction
• Optimised Q-factor for road cycling efficiency
• Compatible with 24mm HollowTech2-style bottom brackets
• CNC machined, hand-polished, and anodised for precision
• Multiple lengths and finishes to suit your bike
• Proven design trusted since 1991.

Important note: Do not use Shimano Dura-Ace BR9100 with these cranks. The design of the BB, Shimano crank, and bearings/seals can cause the lock ring to rub against the BB cup. All other bottom brackets are compatible.