Inspection and testing of bicycle parts, factory inspection services

As a widely used means of transportation, bicycles' quality and safety directly impact user experience and brand reputation. For inspectors, conducting product, factory, and final inspections of bicycles and their components, a thorough understanding of the inspection items, testing methods, and acceptance criteria for each component is crucial. This article systematically outlines the inspection process and key quality control points for bicycle components, based on national standards and industry practices.

1. Classification and Inspection Scope of Bicycle Parts

Bicycle parts can be divided into six categories according to their functions, and inspection must cover all categories:

1. Supporting parts : frame, front fork, saddle, handlebars, bracket, etc.;

2. Transmission components : pedals, crank sprockets, bottom bracket, chain, flywheel, etc.;

3. Rolling parts : rims, front and rear axles, spokes, steel balls, tires, etc.

4. Braking components : ordinary hand brake, caliper brake, cantilever brake, expansion brake, holding brake, foot brake, etc.

5. Speed-changing components : speed-changing shaft, transmission, multi-speed flywheel, derailleur, etc.;

6. Other accessories : fenders, chain guards, bells, locks, lights, tire pumps, etc.

Inspectors should clearly define the inspection scope and sampling plan based on the order, letter of credit or technical agreement to ensure that all parts categories are covered.

2. Quality Requirements and Inspection Basis for Bicycle Parts

1. Implementation standards <br>Mainly based on the national standard GB/T 3564-3566-93, which covers naming, safety requirements, assembly process, technical conditions, and test methods. Export products must also comply with the standards of the target market (such as CPSC, EN/ISO).

2. Quality requirements for key components

   • Middle axis : electroplating/electrophoresis treatment, swing sensitivity ≥50 times (220g pendulum);

   • Front and rear axles : The disc holes are offset by ½ the hole pitch; the swing sensitivity is ≥120 times for the front axle and ≥100 times for the rear axle (175g pendulum); the radial and end face runout is ≤0.3mm;

   • Flywheel : flexible reversal without sticking, outer shell/body hardness ≥75HRA, radial/end face runout ≤0.4mm;

   • Chain : bending degree (100 sections folded in half) ≤ 70mm, breaking force ≥ 8010N;

   • Brake : Braking performance must meet dry (24km/h braking distance ≤5.5m) and wet (16km/h braking distance ≤15m) requirements.

3. Appearance and surface treatment <br>According to SN/T 0248.2-93, check whether there are defects (such as scratches, blistering, fading, rust, etc.) on electroplated and painted parts.

3. Inspection Items and Methods for Bicycle Parts

Inspection should cover appearance, size, accuracy, strength, quantity, packaging and marking, etc. Specific methods include:

1. Sensory evaluation <br>Use tools such as calipers, thread gauges, and color charts to check specifications, color, and surface finish quality. If the initial inspection failure rate exceeds the limit, double sampling and re-inspection will be required.

2. Precision measurement <br>Use dial indicators, flat plates, special fixtures, etc. to measure radial/end face runout, parallelism, perpendicularity, etc. A batch is considered unqualified when the unqualified rate is greater than 10%.

3. Strength test <br>Simulates actual stress environment (such as chain breaking force, brake performance), adopts GB2828 sampling scheme, and uses Ac/Re value as the basis for judgment.

4. Durability and corrosion testing

   • Salt spray test (electroplated parts), adhesion test (paint film);

   • Fatigue test (simulating reciprocating force during cycling).

IV. Key points for pre-assembly inspection and vehicle commissioning

During factory inspections or production line spot checks, focus on pre-assembly status and vehicle commissioning:

1. Component status check

   • Is the inner wall of the front fork bushing smooth and free of burrs?

   • Check whether the riser and sleeve fit tightly and whether there are any scratches after disassembly and assembly.

2. Assembly quality inspection

   • Handlebar : Insertion depth ≥ marked depth, steering is flexible and without stiff points;

   • Middle shaft : flexible rotation, locking torque ≥ 30N·m;

   • Wheel : radial/end runout ≤ 2mm (aluminum wheel ≤ 1.5mm), spoke tension ≥ 300N;

   • Pedals : The left and right threads are clearly marked and work well with the cranks;

   • Chain : runs smoothly without jamming, chain breakage or friction;

   • Brake : Reliable braking, quick reset of the brake handle, and the firmness of the connection parts ≥980N.

3. Safety and Compliance Program

   • Protrusions : Length > 8mm need to be rounded (R ≥ 6.3mm);

   • Reflectors : front (white), rear (red), side (white/yellow), and footrest (yellow) must be complete and meet color matching requirements;

   • Speed ​​Shifting System : Accurate gear shifting, no chain falling off and no neutral gear.

5. Common inspection issues and quality control suggestions

1. Typical defects

   • Poor electroplating/painting: rust, blistering, peeling;

   • Size deviation: hole position deviation, excessive runout;

   • Function failure: inaccurate speed change, excessive braking distance, chain breakage;

   • Assembly problems: threads not tightened, parts loose and making abnormal noises.

2. Key points of factory audit

   • Verify whether the supplier's quality control system is sound;

   • Review production records, inspection reports and standardized operating procedures;

   • Evaluate storage conditions (moisture prevention, rust prevention, batch management).

3. Packaging and shipping inspection

   • The packaging must be firm, moisture-proof, suitable for transportation, and clearly labeled (name, specifications, gross/net weight, batch number, etc.);

   • If the storage period exceeds 1 year or there is damage, re-inspection is required;

   • During the shipping process, the goods must be loaded and unloaded carefully to avoid damage to the packaging.

VI. Conclusion

Bicycle component inspection is a multi-dimensional, systematic quality assessment process encompassing materials, craftsmanship, assembly, performance, and packaging. Inspectors must be proficient in both national standards and customer requirements, integrating sensory evaluation, instrumental measurement, and functional testing to comprehensively assess product quality. Companies should establish a comprehensive quality control system from raw materials to finished product, and conduct regular factory inspections and tests to ensure product compliance with safety and performance standards, thereby enhancing market competitiveness. At China Huibang Focus, we specialize in product inspection and quarantine, testing and certification, supplier background checks, audits, and factory inspections.