Conquer the track with maximum power transfer and smooth rolling resistance. Engineered specifically for Speedline Cranks and built to withstand the explosive torque of BMX racing, this M47 T47-style Bottom Bracket Kit eliminates flex and creaking so every watt of pedal power goes straight to the rear wheel.

Key Features

• Built for Speedline Cranks: Perfectly matches 30mm spindle cranksets for a rock-solid, high-rigidity setup.

• Precision M47 Threading: Features precision-machined $M47 \times P1.0$ alloy cups to secure firmly into the shell, eliminating power-robbing creaks under heavy gate starts and sprinting.

• High-Efficiency Bearings: Loaded with smooth-spinning 6806 sealed bearings ($30 \times 42 \times 7\text{mm}$) and dual rubber/alloy dust covers to keep dirt, water, and track grit out.

• Lightweight Advantage: Tipping the scales at just 116g, it sheds weight from your drivetrain without sacrificing strength or durability.

• Flexible Shell Compatibility: Fits 68mm to 73mm BB shells (with an overall assembly width up to 86.5mm).

What’s Included

• 1x Nylon Inner Sleeve

• 1x Rubber O-Ring ($34 \times 1.0\text{mm}$)

• 1x Left Alloy Cup (AL6061, Left-Hand Thread $M47 \times P1.0\text{-L}$)

• 1x Right Alloy Cup (AL6061, Right-Hand Thread $M47 \times P1.0$)

• 2x Precision Sealed Bearings (6806 / $30 \times 42 \times 7\text{mm}$)

• 2x Dust Covers (Rubber + Alloy)

• 1x DF30 Wave Washer 

Tech Specs

• Spindle Size: 30mm

• BB Shell Width: 68mm – 73mm (86.5mm overall)

• Thread Pitch: $M47 \times P1.0$

• Material: AL6061 Alloy Cups & Nylon Sleeve

• Weight: 116g (Bottom Bracket Assembly) 

Wrench comes with the Speedline Spinner BB kit