It is always a good idea to carry water with you on any ride to keep your hydration levels up and ultimately perform at your best.
When it comes to choosing what type of water bottle & cage set up you require you should consider how long you’ll be riding for and also how much extra weight you’re willing to carry
Generally water bottle cages are mounted on the inner side of the frame underneath your seat post however there are other types of mounts which sit on the rear of your seat post. For the serious triathlete, a specially designed aero bar mount is the ultimate in aerodynamic hydration.
Choosing a water bottle is a less involved process with many people simply opting to choose one which matches the colour scheme of their bike. You should however look out for water bottles that are made from BPA free materials in a size that will fit your cage.