Beijing Knot walking to Ox Edge and camping options?

Hi, Johann.
1. I will set Dongzhimen Transportation Hub as the start point. You can take bus no.866 to Caigezhuang Bus Stop and transfer bus no.936 to Yanqizhen Bus Stop. Then you may catch bus no.h25 to Xizhazi Bus Stop. Upon arrival, you may find the 5th Team of Xizhazi Village directly. After a break, you can head for BJ Knot from there. This bus trip may take around 3.5 hours.
2. Well, as I know, you may not finish the part between BJ Knot and Ox Horn Edge in one day. Generally, the visitors will hike to Jiankou Spot on the first day and continue to Ox Horn Edge on the second day. Besides, they will spend overnight in Jiankou Village which is near Jiankou Spot. Because of some steep parts, it may probably take around 5 hours from BJ Knot to Jiankou Spot and about 3 hours from Jiankou Spot to Ox Horn Edge. Ox Horn Edge is near the second team of the Xizhazi Village. You can find the hotels in this village or you may also camp there.

Hey Lisa,
thanks for this elaborate answer! I will probably take the Bus route you recommended and then just walk from BJ Knot to Jiankou Spot, sleep in the village there and drive back down to BJ City as i only have 1 and a half day time.

Hallo I am Nikola from Bulgaria.
I am coming to BJ in September and I want to do hike from Knot to Mutianyu. My question is, I will come to China with lagguage for a long term stay, is there safe place where I can leave most of my lagguage and take only my one or two day hike equipment with me is BJ? (somethink like rent a safe but for 1-2 suitcases).

You could just store your luggage at the Beijing International Airport Luggage Storage Counter beside T2 Gate 10 and east and west sides of T3 Arrival Hall Public Area.