Let’s get this straight: you don’t need a carbon fiber water bottle cage, not even if you are one of those disgustingly skinny cyclists with only 3% body fat. A carbon fiber water bottle cage might save you an ounce (or less) of weight on your bike, but it will cost you at least four times more than a stainless steel bottle cage. However, putting a stainless steel water bottle cage on a carbon fiber bike ought to be banned by international law! The psychological damage to your prized carbon fiber bike would be tremendous and probably keep it from reaching maximum speed—it’s like putting a set of Walmart hub caps on a brand new Mercedes-Benz. So, since you don’t need a carbon fiber water bottle cage, but your carbon fiber bike does, I would suggest you buy a Planet Bike Carbon Fiber Water Bottle Cage.
The Planet Bike Carbon Fiber Water Bottle Cage is incredibly lightweight (only 22 grams) and, compared to other brands, is reasonably priced. I purchased a pair of these cages a couple of months ago and they have worked flawlessly with both 21-ounce Camelbak Podium Chill Bottles and 22-ounce Clean Bottles. They have a very clean design and will serve you well for many years to come.
Earlier this year one of the “carbon fiber” bottle cages on my Trek Madone road bike broke. I had purchased a pair of “carbon fiber” cages when I originally bought the bike a few years ago, but the bottle cages had no markings to identify the manufacturer. While inspecting the broken cage I realized that my “carbon fiber” bottle cage was really made of fiberglass! Since the bottle cage don’t even have a manufacturer’s name on them I don’t even know who to complain to!
My main reason for recommending the Planet Bike Carbon Fiber Water Bottle Cage is simply this: Five or six years from now if you somehow manage to break one of these cages you will find out two things. First, the Planet Bike bottle cage was actually made of carbon fiber, not fiberglass. Second, the Planet Bike bottle cage comes with a limited lifetime warranty against defects in workmanship and material. They put their name on their products and their reputation behind them.
The Planet Bike Carbon Fiber Water Bottle Cage retails for $50, but you can usually find it a bit cheaper online (I bought mine from Amazon.com). These cages are not cheap, but they are still better priced than most of the other bottle cages on the market.