When it comes to choosing a Bidon, we adhere to our friends at Velominati and Rule #52 // Drink in Moderation. "Bidons are to be small in size. 500ml maximum, no extra large vessels are to be seen on one’s machine. Two cages can be mounted, but only one bidon on rides under two hours is to be employed. Said solo bidon must be placed in the downtube cage only. You may only ride with a bidon in the rear cage if you have a front bidon, or you just handed your front bidon to a fan at the roadside and you are too busy crushing everyone to move it forward until you take your next drink. Bidons should match each other and preferably your bike and/or kit." With that in mind, our clear or smoke Rouleur bidons are neutrally designed for maximum flexibility.