ISO 6701:1991

Overview

ISO 6701:1991 specifies the external dimensions of spoke nipples used in bicycle wheels. This international standard applies to both round head and flat head spoke nipples, defining their crucial dimensional characteristics and tolerances. The precise standardization helps ensure compatibility and interchangeability across different manufacturers and bicycle models. The standard also details a clear designation system for these components based on their wire diameters.

Developed by ISO Technical Committee ISO/TC 149 on cycles, this standard supports global uniformity in spoke nipple manufacturing, which is critical for the assembly, maintenance, and repair of bicycle wheels.

Key Topics

• Scope:
  ISO 6701:1991 covers the external dimensions and tolerances of spoke nipples with round or flat heads. It applies specifically to spoke nipples designed for four wire diameters.

• Dimensional Specifications:
  The standard includes detailed measurements such as:

  • Diameter of spoke wire
  • Radius of nipple head dome
  • Diameter and thickness of nipple head
  • Length and width of flats on the nipple head
  • Depth and width of the nipple slot

• Designation System:
  Each compliant spoke nipple is designated by the standard's reference number followed by the wire diameter in millimeters. For example, a spoke nipple with a 2 mm wire diameter is designated as ISO 6701 02.

• Tolerances:
  Defined acceptable tolerances for each dimension ensure manufacturing precision and part interchangeability.

• Visual Reference:
  The standard provides figures and tables illustrating the nipple dimensions, ensuring manufacturers can meet exact specifications.

Applications

ISO 6701:1991 is essential for manufacturers, suppliers, and maintenance professionals in the cycling industry. Practical uses include:

• Manufacturing:
  Bicycle component manufacturers utilize this standard to produce spoke nipples that meet international size and quality requirements.

• Quality Control:
  Ensures that produced nipples conform to dimensional tolerances for reliable performance and fit.

• Bicycle Assembly:
  Standardized spoke nipples facilitate easier wheel building and assembly across different brands and wheel designs.

• Maintenance and Repair:
  Bicycle technicians and users can select appropriate replacement spoke nipples that fit existing spokes without compatibility issues.

• Compatibility Assurance:
  The classification by wire diameter and dimension tolerances ensures consistent compatibility between spoke nipples and spokes from multiple sources.

Related Standards

• ISO 5775: Covers bicycle tire and rim designations, complementary to wheel components like spoke nipples.
• ISO 6691: Specifies spoke tension measurement, linked to the overall quality of wheel performance.
• EN and JIS Bicycle Wheel Component Standards: Regional standards mirroring some aspects of ISO 6701 for local market compliance.
• ISO/TC 149: The technical committee responsible for cycling standards, under which ISO 6701 was developed.

By following ISO 6701:1991, the bicycle industry benefits from standardized spoke nipple dimensions, which improve product quality, maintenance ease, and global interchangeability. This fosters safety, reliability, and consumer confidence in cycling equipment worldwide.