Box Two™ 24mm External bottom brackets feature cold-forged, CNC-machined alloy cups, dual-labyrinth bearing covers, and precision sealed bearings. They are the perfect match to Box Three™, Four ™ cranks, and the ultimate upgrade to the budget BBs sold with most cranksets. Box Two™, 24mm External Bottom Brackets, are designed to fit all 24-millimeter crank spindles and frames with 68 or 73 x BC 1.37-inch bottom bracket shells.

The Box Two M30 bottom bracket is a slightly less acute embodiment of our Oversized technology seen in the M35. Generously sized ABEC-5 bearings help reduce power loss to defection. The larger 30mm cross section is designed to mate up with the rest of the M30 line of Oversized crank sets.

Stable Outboard Bearing Position
Precision Abec-5 Sealed Bearings

Process: CNC-Machined Cups
Material:
• Cups: Alloy
• Sleeve - ABS Plastic
Finish: Anodized
Spindle Type: 24mm
Shell Width: 68/73mm
Thread: 1.37 Inch x 24 TPI (English)
Compatibility:
• Shell: BSA (Euro) Threaded
• Spindle: Box Three™, Box Four™, Shimano HollowTech II, RaceFace X-Type
Weight (+/- 5%): 105 g / 3.7 oz

* Compatibility: Box Three™, Box Four™, Shimano® HollowTech II, RaceFace® X-Type
Material: 6061-T6 Aluminum
Shell Width: 68mm/73mm
Spindle Type: 24mm
Thread: 1.37 Inch x 24 TPI
Weight: 105 grams / 3.7 ounces

* Process: Forged & CNC-Machined Cups
Material:
• Cups: Alloy
• Sleeve: ABS Plastic
Finish: Hard Anodized
Spindle Type: Box/Praxis™ M30 only
Shell Width: 68mm/73mm
Compatibility:
• Shell: BSA (Euro) Threaded
• Spindle: Box One™ M30-M, Box Two™ M30-P
Weight (+/- 5%): 110 g / 3.9 oz