Bicycling holidays have become popular, not only in Thailand. Now I am not a real bicyclist, more a bit of a weekend-bicyclist. So more days trips would be too much for me. But there are many tour operators in Thailand that offer short bicycle trips and some that offer more days bicycle trips. I did write about it before. But yesterday I did read the "Tour Operator" page of "Bicycle Thailand" and I think this is a very complete list of all tour operators in Thailand doing anything with bicycle tours.