I am a little worried about you. Xinxiang is a random urban area in Henan province of no particular interest to motorcyclists; Xinjiang is an enormous province of China to the west full of interest. My worry about you maybe mis-writing a little J is that you are painting China with a wide brush without attention to detail. You might be able to ride a 40 year old motorcycle through Xinjiang with fake papers and have no problem. But, you also might not. You might instead be grabbed by one of the 10,000 military police that the People's Liberation Army recently marched down the streets of Urumqi in a show of force against Islamic terrorism in the province. You will be entering what is regarded (perhaps wrongly) as the most dangerous, most strictly governed province of China, where beards on men have been banned. I have no personal experience in Xinjiang, and I am desperate for a MCMer to come on here, tell me I've got it all wrong, and give us all a safe route to explore that wonderful place. But, it is not a place to assume you are just going to hippie-motor it on through with no complications. Please find people who live in Xinjiang right now who can give you a sense of what's going on, and plan very carefully. I wish you nothing but safe travels.