Bus from Dongzhimen to Simatai (end of Nov.)

Hello, transfer is needed on the way for going to the great wall. You can take bus no. 980 (05:50 - 21:00) or 980 express line (06:00 - 20:00) to Miyun Bus Station. Then transfer to bus Mi 51 (05:10 - 17:30) to Simatai Village Station and walk to the entrance of the Gubeikou Town.

Excellent, A lot of thanks Danielle,
That's what I will do. By the way may be you have an idea of the frequency of these 2 buses. How long would it take for the all trip ?
My return 2 days later will be towards dowtown Huairou, to go to Mutianyu Great Wall.
I suppose I will need to change bus in Miyun station again?

The frequency of 980 Express is about 10 minutes. The bus line Mi 51 departs at 07:30, 08:30, 12:30, and 14:40. The whole trip takes about 3 hours.

To Mutianyu, you may take bus line Mi 51 from Simatai to Mihong Park Station. Next, change to bus line 868 from Jizhuang Village to Huairou Bus Station. Then, take bus line h23 to Mutianyu Roundabout. Upon arrival, walk for about 500 yards to the ticket office. :)

You are really great Danielle ! So many thanks , very helpful . Hope to see you around the great wall !
Jacques .