This is my cycling route around China. It was about 17,000km, and took me 15 months (with quite a few month-long breaks for various reasons).
I roughly followed the initial plan for the first half between Kunming and Beijing, except for really interesting extension through Baiyu and Dege on the Tibetan Plateau, a round trip from Kunming on the Karakoram Highway towards the Pakistan border, and less time spent in the northern half of Xinjiang. The road north from the Taklamakan desert through the Tian Shan mountains (the G217) was really worthwhile. We got half way from Kuche to Dushanzi, which is a bit of a classic route, before turning west towards Ili on account of the road north being blocked by snow.
Once in Beijing the original plan to travel north to Mohe at the Russian border was put aside, and after a round trip to see the start of the Great Wall at Shanhaiguan on the coast, I made a new route south towards Nanjing, and then more directly west towards Kunming, without travelling that far south. This felt sensible given the greater industrialisation along the seaboard, and allowed me to go through some wonderful places like Tai Shan, Huang Shan, Qufu, and Jingdezhen. I really enjoyed the whole of Hunan and Guizhou, even if it was a really challenging hilly route at the start of summer.