GB/T 23657-2018Series of cycle rims (English PDF)

1 Scope

This Standard specifies the dimensions and tolerances of various types of cycle rim contours, and gives the rim contour curve and its main dimensions of the matching part between the tyre and the rim.

This Standard applies to the rims of various series of cycle tyres included in GB/T 7377.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 2933, Wheels and rims for pneumatic tyres - Vocabulary, designation and marking (GB/T 2933-2009, ISO 3911:2004, IDT)

GB/T 6326, Tyre terms and definitions (GB/T 6326-2014, ISO 4223-1:2002, NEQ)

GB/T 7377, Series of cycle tyres (GB/T 7377-2017, ISO 5775-1:2014, MOD)

3 Terms and definitions

For the purposes of this document, the terms and definitions given in GB/T 2933 and

GB/T 6326 apply.

4 Symbols

The following symbols apply to this document.

A Rim width D Specified rim diameter D1 Measured rim diameter D2 External diameter Dm Measuring mandrel diameter G Flange height H, H1 Well depth (unobstructed minimum depth above rim base with rim tape fitted to permit tyre fitment)

L Theoretical tape length L1 Well width (well width above rim tape)

P Bead seat width R1, R2 Flange radius R4 Well top radius R7 Well side radius W Measuring tape width

5 Classification and designation

Designation classified by the rim type and its structure are as follows:

-- Straight side rims (referred to as SS type);

-- Hooked bead type rims (referred to as HB type);

-- Crotchet type rims (referred to as CT type);

-- Beaded edge rims (referred to as BE type).

Implement the scope of application, figures and requirements for main dimensions of the above four types of rims in accordance with the provisions of Chapters 6 ~ 9. See Chapter 10 for the requirements for main dimensions of the rim valve hole. Refer to

Appendix C for the inspection method of rims.

6 Straight side rims (SS type)