Trek RSL Aero Water Bottle + Bottle Cages - Black/Grey

When it comes to bike gear, it’s easy to focus on the big components: frame, wheels, gears and power meters. But one of the most underrated – and most important – components on your bike is the water bottle cage. It keeps you hydrated at all times, and it can be the difference between keeping your cadence up all the way home or crashing on the way. As the range of water bottle cages has grown, it’s also become more important to choose the right type – tailored to your needs, your setup and your ambitions.

Bottle cages come in many shapes and materials – from lightweight carbon fiber versions to robust models in aluminum or plastic. There are the classic locations on the down tube and seat tube, but also special solutions such as BTA (Between The Arms) between the bars, behind-the-saddle systems and aero-integrated holders, which are especially popular with triathletes and competitive riders. What they all have in common is that they should hold your water bottle securely – whether you’re riding cobblestones, gravel or 180 km on an Ironman route.

The choice of bottle cage should not be random – it should be based on your way of cycling, your bike type and your fluid needs. If you ride long distances or triathlon, it is a good idea to consider more than two bottles on the bike. This is where alternatives such as BTA solutions and behind-the-saddle mounts come into play. A BTA bottle holder is typically mounted between the arms of the tri handlebar and makes it easy and quick to get fluid without having to move your gaze too much. It is not only practical – it is also aerodynamic and energy-saving.

Behind-the-saddle solutions are another popular choice among triathletes and long-distance exercisers. They provide space for one or two extra bottles and free up space on the frame for, for example, a toolbox or aerodynamic bottles. However, they require you to be used to reaching behind and gripping the bottle securely – a technique that takes some getting used to. In return, you get the opportunity to carry up to three bottles without overcrowding the frame.

If you are more into classic road cycling or gravel, the traditional locations are often the most obvious. Here it is more about fit and grip. A good bottle cage should be able to hold the bottle securely, even when the surface gets uneven – but at the same time allow quick access when you need to drink. On gravel bikes with extra mounting points, many also choose to add an extra holder under the down tube, so you can carry more fluid on long rides.

When choosing a bottle cage, it’s also worth considering which features you prioritize most. Is it light weight, aerodynamics, ease of use or secure hold? Many competitive riders opt for ultralight or aerodynamically optimized models, which are designed to minimize drag and save seconds. These bottle cages are often designed with specific bottles and locations in mind and can be a bit more expensive – but they can be worth the investment if you’re looking for marginal gains.

For recreational riders and daily workouts, it's more about functionality and reliability. Here, a flexible bottle cage with a good grip often makes the most sense. The choice of material also matters: Carbon fiber is light and stiff, but can be more fragile if you drop the bike or squeeze the bottle hard. Aluminum and reinforced plastic are more durable and budget-friendly – and often just fine for most needs.

Finally, there’s the aesthetic aspect. Bottle cages come in a variety of colors and designs, so you can match your bike and other gear. It may seem like a small detail, but for many riders, the overall look is huge. A bottle cage that fits properly and looks good is just one small but important part of a well-equipped bike.