Hello Robin,
I agree with Luke, Dave and Ian, that access to riding areas is never far away from anywhere you might choose to live in or around CNX. I currently live just south of CNX, in Hang Dong, on the entrance road to Ob Khan National Park, which is a fantastic area for off-road riding, whether on dirt bike or mountain bike. Numerous trails and single track right on my doorstep! With the dual lanes on the Irrigation Canal Road currently being extended all the way to San Patong, CNX city access from Hang Dong will be a lot faster in the near future (15 minutes). But the Mae Rim area would be just as good a place for a dirt/mountain biker to set up base camp. The best thing to do is to hang out and cruise around for a while and discover the various areas yourself. The convenience of living in Hang Dong is its closeness to the airport and shopping facilities. Cnx's best shopping mall Central Airport Plaza as well as Tesco Lotus, Rimping and the soon-to-open Big C supermarkets are all located on Hang Dong Road.
When are you planning to move to CNX? I'm glad to see a new off-roader setting up camp here, as there are only a few expat dirt bikers around (the GT-R community consists almost entirely of road riders).