Promax EX-1 Bottom Bracket
Best durable upgrade for competitive BMX and track cyclists.
This is the reliable, no-nonsense upgrade your drivetrain needs when stock components inevitably fail. By prioritizing precision-sealed bearings and robust weatherproofing over flashy gimmicks, it delivers a noticeably smoother pedal stroke that stands up to the elements without requiring constant maintenance.
$54.99
More EX-1 options
Who it's for
- BMX racers seeking reliable components for high-intensity track use
- Competitive riders prioritizing mechanical efficiency and low rolling resistance
- Mechanics looking for a straightforward fit on standard threaded frames
Who should skip it
- Cyclists with non-standard or smaller diameter crank spindles
- Home mechanics without a dedicated external bottom bracket wrench
- Weight-conscious racers aiming for the absolute lightest build possible
Performance breakdown
Bearing Smoothness
Precision-sealed internals ensure a fluid, low-friction pedal stroke.
Weather Resistance
Dual-labyrinth seals effectively block grit and moisture from entering.
Structural Rigidity
Cold-forged alloy cups provide a stiff, reliable platform for power transfer.
Installation Ease
Standard BSA threading makes this a straightforward swap for most frames.
Compatibility Range
Works seamlessly with almost all common 24mm spindle cranksets.
Weight Efficiency
Solid alloy construction prioritizes durability over ultralight racing performance.
Key Specs
Material
Aluminum
Weight
103 grams
Bottom Bracket Standard
BSA Threaded
Spindle Interface
Shimano Hollowtech II
Spindle Diameter
24 mm
Shell Width
68 mm
Sealing Type
Labyrinth Seals
Water Resistant
Yes
Intended Use
Cycling
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