... . Company Profile XI'AN CHANGDA METALWORK CO.,LTD which located in the historic, ancient Chinese city ... 4. After-service. a. In production and after delivery, we will track on time and tell your goods situation.b. ... the world.What’s your annual bike frame production capacity?Around 2500 sets. 6. Are you ... ,TUV,SGS,CAS,CNAS certification. for all production process, we have standard rules.Secondly, we have ...