I want to travel by mountain bike alone. The route is from Shenzhen to Ningxia to Qinghai and back. Please help me calculate the distance, preferably the national highway.

It is safe to drive on the national highway, so it is not advisable to get lost. The general route is as follows:

First to Yinchuan and then to Qinghai: from Shenzhen to Xinyang, Henan Province along National Highway 107, then to Xi 'an in the northwest along National Highway 3 12, then to Xi 'an in the north, then to Yinchuan in the south along National Highway 2 1 1, to Yinchuan in the south along National Highway 109, and to Qinghai via Lanzhou.

Return trip: Depart from Xining and return to Lanzhou eastbound along National Highway 109. In Lanzhou, transfer to National Highway 3 16 to Nanping, Fujian, and return to Shenzhen South along National Highway 205.

The total length is estimated to be 5600-5800 kilometers, which is about 6000 kilometers. At the speed of 150 km per day, it takes an average of 40 days.

You can go faster. Most of the time, it is downwind or crosswind affected by the monsoon, and it will be a little headwind when it comes back.

The average speed is not recommended to be too fast. Riding a long distance is not a short race. You should distribute your physical strength reasonably, adapt to it for a few days, and find a rhythm that suits you. Don't blindly pursue speed. It is suggested that it should be around150km per day. These are all personal opinions.