I. Scope and Terminology
This specification applies to off-road two-wheeled off-road motorcycles, i.e., models designed specifically for unpaved roads, used in off-road racing or recreational activities, and not suitable for public road use. The corresponding road reliability testing and vehicle assembly processes must respectively meet specific technical specifications and process requirements to ensure the reliability, consistency, and safety of the product under complex operating conditions.
II. Vehicle Assembly Technical Requirements
The assembly process should be based on product drawings and process documents, establishing quality control points and inspection control points, and clearly defining the basic conditions such as personnel, equipment, site, and environment. The key assembly points for critical connections and assemblies are as follows: Screw/bolt connections must be tightened symmetrically and in stages, generally exposing 1-2 thread pitches and ensuring the bearing surfaces are in contact; pin connections should be inspected based on contact length and distribution; interference fit connections should have their pressing/heating/cooling process determined by the material and fit, controlling heating temperature and ensuring one-time installation; rolling bearings should be cleaned before assembly, and grease-lubricated bearings should generally be filled with grease to about 1/2 of the cavity, avoiding force transmission through the rolling elements and cage during press-fitting; when sprockets and chains mesh, the geometric center planes of the driving/driven sprockets should coincide, with an offset not exceeding two-thousandths of the center distance between the two sprockets, and the sag of the non-working side of the chain should be 1%-5% of the center distance; brakes should have their free clearance adjusted according to type (e.g., belt type 1-2 mm, shoe type 0.25-0.5 mm); gears and gearboxes should have their contact spots and side clearance checked according to GB 10095 and GB 11365, and the mating surfaces of the gearbox should not be able to be inserted with a 0.05 mm feeler gauge after tightening; hydraulic/pneumatic system assembly should follow GB/T General technical conditions such as 3766 and GB/T 7935 ensure sealing and cleanliness.
III. Road Reliability Testing Specifications
Test vehicles must not be modified without authorization. Testing must be conducted according to designated routes and mileage. Daily cleaning, inspection, and tightening must be completed, and the handling, power, braking, and fluid status must be confirmed. Testing organization and mileage requirements include: daily forest road ≥70 km, track road ≥50 km; total mileage for newly developed models: adults 2000 km, teenagers 1500 km, children 800 km; total mileage for models with significant structural adjustments: adults 1500 km, teenagers 1000 km, children 500 km; total mileage for models with structural component adjustments/improved mature performance components: adults 1000 km, teenagers 800 km, children 300 km. Faults are categorized by severity as A. Fatal/B. Serious/C. Moderate/D. Minor, with corresponding termination/evaluation/repair and continuation/resolvement and continuation principles. Test output must include complete documentation such as inspection and maintenance records, fault records, and road test reports to ensure traceability and closed-loop improvement.
IV. Test Vehicle Setup and Maintenance Guidelines After delivery, the new vehicle will undergo approximately 70 km of road break-in, with the maximum throttle opening ≤60%. During reliability testing, engine speed will be increased as much as possible while ensuring safety; jumping movements are not restricted. Maintenance: Air filter will be checked every 2 hours (on-site) / every 4 hours (forest trails, highways) according to operating conditions; intake system will be cleaned every 20 hours; engine gear oil will be changed every 20 hours (addition amount matched to the model, example value 900 ml); chain will be lubricated daily; engine oil will be changed for the first 500 km, and then every 1000 km; transmission/gearbox oil will be changed every 3000 km; filter maintenance will be performed according to type (e.g., sponge filter cleaned every 500 km, paper filter cleaned every 500 km and replaced every 3000 km). The aforementioned cycles and thresholds should be dynamically adjusted based on environmental dust, load, and intensity.
V. Personnel, Venue, Protective Gear, and Compliance Boundaries
Test riders should possess legal qualifications and off-road riding capabilities, and complete training and assessments in safety awareness, vehicle inspection, driving record keeping, fault diagnosis, and basic repair. Throughout the test, riders must wear certified helmets, elbow pads, knee pads, and body armor (large displacement/full-size models should be equipped with off-road boots), racing suits, and gloves; neck protectors/back panels may be added if necessary. Vehicle management follows the principle of "dedicated personnel management, strict prohibition of private use and riding," and vehicles must be returned to their designated locations after testing. Regarding compliance, it should be clearly stated that this type of vehicle is not suitable for public road use. There are differences in regulatory thresholds for registration and road use (such as lights, rearview mirrors, noise, emissions, etc.). The latest mandatory national standards and local management requirements must be followed to avoid illegal use.
