The bike route around the North-East part of Qiandaohu is amazing. For the entire (about 50km) way it is a strictly separate bike path. Long stretches are completely unique cycleways, and when running alongside the road it is a physically separated cycle way.
Along the way there are tunnels with the walls painted, curvy sections hugging to the hillside and offering spectacular views.
It is best enjoyed going clockwise.
Cycling in this area is hugely popular, so I guess this will be busy during the weekend and holidays. I strongly recommend to go early mornings. The air is fresh and you have the route to yourself.