I got an email from the seller that the bottle cages are indeed mounted on a custom bracket. I had never seen anything like this, but hey, if it works, probably better than strapping on the camel back. After passing out 3 times in my younger years from heat exhaustion, I now over hydrate and get just a wee bit nervous when riding on the longer rides here in humid, hot Florida without having at least one water bottle in reserve. Not easy when I ride one of the single bottle cage bikes from my collection. Mark is right, that extra bottle (or two) in the jersey pocket does get old after awhile. Lou Deeter, Orlando FL