Cycling

The Northern Route out of Chiang Mai (Chiang Mai - Mae Taeng - Chiang Dao - Tha Ton - Chiang Rai - Chiang Mai) via Highway 107 is increasingly popular with cyclists. There is accomodation at reasonable intervals (30km or 60km depending on your requirements) and the route itself is very beautiful in places but not too demanding. Those that favour the shorter daily rides then have time to explore the interesting countryside adjacent to the highway.
For 3 interesting cycle routes around Chiang Dao click here.
Apart from the road cycling, mountain bikers can enjoy a wealth of rough tracks around the area.