TONGTU BICYCLE (GUANGZHOU) CO., LTD. OEM/ODM E-bike Manufacturer GELEISEN Sport Electric Bicycle with LWTOO 7 Speed Derailleur_TONGTU BICYCLE (GUANGZHOU) CO., LTD. is a full chain technology-based Electric Bicycle enterprise that integrates production, research and development, sales, and after-sales service. Its brand GELEISEN E-bike are popular worldwide.