The following is the method to check the quality of the road bicycle bend arm and dental disc after processing:

1. Quality inspection of curved arm

1. Check appearance

- Visual inspection: First observe the surface of the curved arm with the naked eye to see if there are obvious scratches, pits, cracks and other defects. The surface should be smooth and flat, without obvious processing marks or defects. Especially for the carbon fiber bend arm, it is necessary to check whether the resin on the surface is uniform and whether there are fibers exposed.

- Color check: If the arm is coated or painted, check whether the color is uniform and there is no color difference. For the aluminum alloy bend arm, the color after surface treatment such as anodizing should meet the requirements, and there should be no spots, fading and other phenomena.

2. Dimensional accuracy measurement

- Length measurement: Use a caliper or micrometer with appropriate accuracy to measure the length of the curved arm. Compare the measured value with the design size, and the size deviation should be controlled within the specified range (for example, ±0.1mm). The specific tolerance requirements of the bend arm may vary from model to model and design, but should generally be kept within a small deviation range to ensure proper assembly with the frame and foot.

- Width and thickness measurement: Also measure the width and thickness of the bend arm with a suitable measuring tool. These dimensions are crucial for the strength of the arm and its fit with other components. For example, the width and thickness of the connection part with the foot shaft directly affect the stability and force transfer efficiency of the stampede.

- Hole size measurement: Check the dimensions of connecting holes and threaded holes on the arm. Including the size of the aperture, the depth of the hole and the accuracy of the hole position. For example, the position deviation of the mounting hole connected to the frame should be controlled within a very small range to ensure the accuracy and stability of the installation. You can use the internal micrometer, depth ruler and other tools for measurement, hole size deviation is generally required to be within ±0.05mm.

3. Mechanical properties test

- Strength test: tensile test, compression test and other methods to test the strength of the bend arm. The bending arm is fixed on a special mechanical test equipment, and gradually increasing tension or pressure is applied until the bending arm is broken, and the force value at this time is recorded and compared with the strength index required by the design. For the road bicycle bend arm, it is generally required to withstand large trampling force and various complex stresses without fracture or permanent deformation.

- Stiffness test: Using bending test and other methods to detect the stiffness of the bend arm. The deformation of the bending arm is measured under certain loading conditions. Insufficient stiffness may lead to excessive bending of the arm during riding, which affects the stomping efficiency and handling performance. According to different design and use requirements, the stiffness of the bending arm should meet the corresponding standards.

- Fatigue test: Simulate the repeated loading in the actual riding process, and carry out fatigue test on the bending arm. Through a certain number of cyclic loading (such as hundreds of thousands or even millions of times), observe whether the bending arm cracks, deformation and other signs of fatigue damage. This is essential to ensure the reliability of the arm during long-term use.

4. Check the connection parts

- Thread quality check: for connection parts with threads, such as threaded holes connected with pedals or other components, use tools such as thread gauges to check whether the specifications of the threads meet the standard. Check the parameters of the thread shape, pitch, etc., to ensure that it can fit well with the corresponding thread components. At the same time, check the surface quality of the thread, whether there are burrs, missing teeth and other defects.

- Assembly match inspection: test assembly of the crank arm and related parts to check the fitting accuracy of the assembly. For example, the fit with the pedal shaft should be tight and flexible, without obvious gaps or stuck phenomena. The connection part with the frame should be stable after assembly, without loosening or shaking.

Second, dental disc quality inspection

1. Check appearance

- Tooth shape appearance: visually check the appearance of the teeth of the tooth disk, see whether the tooth surface is smooth, there are no burrs, broken teeth and other defects. The edges of the teeth should be neat, with no obvious machining marks or deformation. Any tooth shape defects may affect the mesh effect with the chain and transmission efficiency.

- Platter surface: Check the surface quality of the platter to see if there are scratches, oxidation, rust and other conditions. For aluminum alloy dental disk, after surface treatment of the disk should have good appearance and protection performance. For the steel disk, the surface of the anti-rust treatment should be complete, no rust spots and other problems.

2. Dimensional accuracy measurement

- Outer diameter measurement: Use a measuring tool to accurately measure the outer diameter of the dental disk. The accuracy of the outer diameter size has an important impact on the correct fit of the tooth disc with the chain and the installation clearance with the bicycle frame. The outer diameter deviation should generally be controlled within a small range (such as ±0.1mm), and the specific tolerance requirements of different specifications and models of dental discs may be different.

- Aperture measurement: Measure the center hole aperture of the disk and the mounting hole aperture. The accuracy of the center hole aperture is directly related to the assembly accuracy of the tooth disk and the bicycle shaft, and the mounting hole aperture affects the connection degree of the tooth disk and the crank and other parts. The size deviation of the aperture is generally required to be within ±0.05mm.

- Tooth thickness measurement: Measure the thickness of the tooth disc with a suitable measuring tool. The precision of the tooth thickness is very important for the meshing gap with the chain. Too large deviation of the tooth thickness will lead to the poor fit between the chain and the tooth disk and affect the transmission performance. The tooth thickness deviation should be controlled within ±0.05mm.

3. Tooth shape accuracy detection

- Profile measurement: Use a special tooth profile measuring instrument, such as a gear measuring instrument, to measure the profile of the teeth. Ensure that the profile of the tooth meets the design requirements, and the deviation from the standard tooth is within the allowable range. Too much deviation will lead to problems such as skipping teeth and stalling during the engagement of the chain, which will affect the smoothness of riding.

- Pressure Angle measurement: accurately measure the pressure Angle of the teeth. The pressure Angle is one of the important parameters to determine the meshing performance of the chain and the tooth disk, which should conform to the design standard. Different transmission systems and transmission requirements may have different pressure Angle designs, and the general deviation should be controlled within a small Angle range (such as ±0.5°).

4. Dynamic balance test

- Install the tooth tray on the dynamic balance test machine to simulate its state when rotating at high speed. By measuring the unbalance of the tooth disk during rotation, the dynamic balancing performance is judged. If the unbalance is too large, it will produce vibration and noise during riding, affecting the comfort of riding and the service life of the dental disc. Generally, the unbalance of the dental disc is controlled within a certain range (according to the specific design and use requirements), and the unbalance requirements are more stringent for high-performance road bicycle dental discs.

Through the above comprehensive quality inspection method, it can effectively ensure that the quality of the road bicycle bend arm and dental disc meet the requirements, so as to ensure the performance and safety of the bicycle.