Specifications

• Use: Crank Arm Bolt

  • Specifically designed for use with crank arms on bicycles, providing secure attachment to the bottom bracket spindle. This bolt helps ensure that the crank arm remains firmly in place under pedaling forces and maintains drivetrain stability.

• Size: M7 x 1.0 x 18mm

  • Diameter (M7): This bolt has a 7mm diameter, slightly narrower than typical M8 crank bolts, allowing it to fit cranksets with a smaller interface. The M7 size is less common but often found in certain specialty or vintage crank designs.
  • Thread Pitch (1.0mm): This thread pitch denotes fine threading, which provides a secure fit and resists loosening under vibration, commonly beneficial in bicycle applications where stability is key.
  • Length (18mm): The 18mm length provides adequate depth for secure insertion into the crank arm interface. This length allows for enough thread engagement to prevent loosening and enhance the stability of the crank arm.

• Material: Steel

  • Constructed from high-quality steel, providing strength and durability for regular use and resistance to the stresses encountered in cycling. Steel bolts are ideal in cycling applications due to their resilience and ability to withstand repeated high-torque applications, particularly in single-speed or heavy-duty drivetrains.

• Color: Black

  • Finished with a black coating that adds a layer of corrosion resistance and durability. This color also complements many bike designs, providing a sleek, unobtrusive look in combination with the crank arm.

• Brand: AltaLine

  • Known for its reliable bike components, AltaLine offers sturdy, well-manufactured hardware suited for various bicycle types, including mountain, urban, and BMX bikes. Their parts, like this crank arm bolt, are engineered to high-quality standards.

Key Features and Benefits

1. Enhanced Stability

   • The M7 diameter and fine 1.0mm thread pitch are designed to keep the crank arm securely attached to the spindle, minimizing any potential play or movement. This is critical for maintaining power transfer efficiency and stability in the drivetrain, particularly during intense pedaling.

2. Corrosion Resistance

   • The black finish not only adds aesthetic value but also protects the steel from rust and corrosion. This is beneficial for bikes exposed to varied weather conditions or moisture, as it helps ensure long-lasting durability.

3. Wide Compatibility

   • While M7 is not the most common size for crank arm bolts (M8 is more typical), this bolt is compatible with cranksets requiring an M7 fitting, making it a specialized component suitable for certain crank designs. This can include some vintage or BMX cranks that are not standard size.

4. Secure Fitting

   • The bolt’s 18mm length is ideal for creating a secure hold in the crank arm, ensuring that it remains fixed to the spindle and reducing the chance of loosening over time. The fine threading enhances its grip and prevents backing out under vibration.

Typical Applications

• BMX Bikes: Some BMX bikes, particularly those with single-speed or high-durability drivetrains, use specialized crank arm bolts like this one.
• Vintage and Custom Bikes: Certain vintage or custom bike builds may require M7 crank bolts, where this bolt would be an ideal fit.
• Single-Speed and Track Bikes: Bikes with minimalistic or single-speed designs often benefit from a solid crank arm attachment, making this bolt useful in certain track bike setups.

Compatibility Considerations

The Crank Arm Bolt is ideal for crank arms and bottom brackets with an M7 bolt interface. It’s important to ensure that the crank arm and spindle are compatible with M7 bolts, as this size is less standard compared to M8 bolts. It’s especially common in specialty or vintage designs where M7 threading was used.