How long is the warranty period for modified parts? What is the after-sales process if damage occurs?

Warranty does not cover damage caused by accidental collision or improper modification. For non-artificial faults of parts, replacements are available with order and installation records. Warranty terms for wearing parts including wheels, brakes and exhaust systems are marked separately. Products can be sent back for inspection nationwide, and round-trip shipping fees shall be borne according to liability attribution.