I have lately been in the process of doing a lot of Mountain Biking, and Road Bike riding. Since it is quite hard to find these spots on an english language website, I will share what I have learned so far.
Road Biking:
I personally like to ride out by the new airport. There is a large shoulder, the pavement is new, and if you just want to stay on less traveled section of road you can. One loop can be made into 25K. I reccomend staying as far left to the shoulder as possible, and stay there. Motorbikes still pass at a fast speed, and are your biggest threat. Parking at the base of this control tower. 13°41'48.16"N 100°46'15.92"E
The famous bike route in BKK seems to be on the South side of rama 9 closer to the airport, but I personally think it is a pain in the ass to get to, and it still seems like a busy road.
KB Route. I have not been here yet, but plan to check it out soon. 13°48'47.22" N 100°40'35.61"E
I have also been riding south of Chon Buri. Plenty of good roads with not many hazards down there. Parking 13°13'33.02"N 100°58'19.03"E
Plenty of great roads to ride up around Kao Yai also. Stay at some resort, and go riding.
Mountain Biking
I will just copy and paste a few of these websites, as they have pictures and descriptions.
http://www.mountainbiketoursthailand.com/single_track_trail_khao_e_to_green.html
http://www.mountainbiketoursthailand.com/single_track_chon_buri.html (Lots of sandy patches, and not much downhill) Parking 12°57'30.06"N 101° 2'20.90"E
http://www.everytrail.com/view_trip.php?trip_id=997473 Parking 14°29'48.13"N 101° 8'34.17"E
If anyone has some more to share, please do
Road Biking:
I personally like to ride out by the new airport. There is a large shoulder, the pavement is new, and if you just want to stay on less traveled section of road you can. One loop can be made into 25K. I reccomend staying as far left to the shoulder as possible, and stay there. Motorbikes still pass at a fast speed, and are your biggest threat. Parking at the base of this control tower. 13°41'48.16"N 100°46'15.92"E
The famous bike route in BKK seems to be on the South side of rama 9 closer to the airport, but I personally think it is a pain in the ass to get to, and it still seems like a busy road.
KB Route. I have not been here yet, but plan to check it out soon. 13°48'47.22" N 100°40'35.61"E
I have also been riding south of Chon Buri. Plenty of good roads with not many hazards down there. Parking 13°13'33.02"N 100°58'19.03"E
Plenty of great roads to ride up around Kao Yai also. Stay at some resort, and go riding.
Mountain Biking
I will just copy and paste a few of these websites, as they have pictures and descriptions.
http://www.mountainbiketoursthailand.com/single_track_trail_khao_e_to_green.html
http://www.mountainbiketoursthailand.com/single_track_chon_buri.html (Lots of sandy patches, and not much downhill) Parking 12°57'30.06"N 101° 2'20.90"E
http://www.everytrail.com/view_trip.php?trip_id=997473 Parking 14°29'48.13"N 101° 8'34.17"E
If anyone has some more to share, please do