Hydration Systems

A triathlon drinking system, also called a torpedo drinking system or BTA system (Between-The-Arms), is an integrated hydration solution that is mounted on or between the aerobar extensions and that lets you drink while riding in time trial position. The system is positioned so that you have the straw or the mouthpiece directly in front of you without having to take your hands off the supports or sit upright. That is the core advantage compared to a standard bottle in a frame cage: you fully maintain the aerodynamic position while drinking, which gives both a time advantage and a concentration advantage on the bike leg of a triathlon or during a time trial.

In this range you will find torpedo drinking systems in volumes from 125 ml to 880 ml for short and long distances, compact bottle cages in torpedo style that hold a standard bottle on the aerobar, low-profile systems that are mounted between the front fork or stem, and separate accessories such as replacement straws, refresh kits and bracket kits for mounting. The choice depends on the type of race, how long you ride, how much you want to drink and whether you want a complete integrated system or a cage that holds a standard bottle. Always combine a drinking system with a triathlon handlebar that offers the space and mounting points the system needs.

Which drinking system suits you?

The choice is determined by the distance you ride, how much you want to drink and how you want to attach the system to your bike.

You ride a sprint triathlon or short time trial up to 40 kilometres: a compact system of 125 to 200 ml is sufficient. On a sprint or olympic distance you take little drink with you on the bike because the leg is short and you have the opportunity to drink at the laps on the course. A small torpedo bottle cage or mini drinking system keeps the frontal area of the bike minimal and adds hardly any weight.

You ride a half triathlon or longer time trial of 80 to 90 kilometres: choose a drinking system of 500 ml with an integrated straw and a volume indicator. On the half triathlon distance you ride one to one and a half hours and need a substantial fluid intake to stay hydrated. A 500 ml torpedo drinking system with indicator visibly shows you when the system is empty, so that you know when you should switch to a bottle from the back of the saddle.

You ride a full triathlon or a time trial of more than 90 kilometres: consider a larger system up to 880 ml or a combination of a front torpedo system and saddle bottle cages at the rear. On a full triathlon you ride more than four hours on the bike and have to drink consistently. A large front drinking system ensures that you always have drink at hand in the aero position; the bottles at the back serve as a reserve and for refilling at the transition zone.

You have an aerobar and want to hang a standard bottle at the front: choose a bottle cage in torpedo style. A torpedo bottle cage is an attachment system that holds an ordinary 500 ml bottle horizontally between the aerobar extensions. You do not drink from it via a straw but lift the bottle out. That is less aerodynamic than an integrated drinking system, but handy if you already have bottles and do not want to purchase a new system. Torpedo-style bottle cages are available in versions for 125 and 500 ml bottles.

You also want to mount a GPS computer on the cockpit: choose a BTA bottle cage or drinking system with an integrated GPS mount. Some BTA bottle cages are equipped with an attachment point for a bike computer on top of the system, so that your GPS device is directly visible in front of you while you ride in the aero position. That saves a separate GPS mount on the aerobar and keeps the cockpit clear. Also take a look at the bottles and bottle cages for additional hydration options at the back of the saddle.

What to look for when buying a drinking system?

Volume and distance

Volume is the first variable. A system of 125 to 200 ml suits sprint and olympic triathlons where the bike leg is short. A volume of 500 ml is the most used format for half and full triathlons: it offers enough content for a bike leg of 80 to 90 kilometres at an average fluid intake. Systems of 880 ml are suitable for ultra triathlons, long time trials and athletes who drink more than average. Bear in mind that a larger volume also means more weight and a larger size, which has an influence on the aerodynamics of the front of the bike.

Integrated system or bottle cage

An integrated torpedo drinking system has a fixed reservoir with a straw or mouthpiece from which you drink without having to take the bottle out. You can refill the reservoir via an opening on top or by uncoupling the system. A torpedo bottle cage holds an ordinary standard bottle horizontally and lets you take the bottle out for drinking. An integrated system is more aerodynamic and easier to use during the ride; a bottle cage is more flexible and suitable if you already have bottles or want to switch them quickly.

Volume indicator

Some torpedo drinking systems have a transparent side wall or an indicator that shows how much fluid is still in it. That is practical during races where you do not want to think about how much you still have: you see it directly. Systems without an indicator are usually more compact or cheaper, but require you to keep track of when you refilled the system and how much you have drunk.

Mounting points and aerobar compatibility

Torpedo drinking systems are attached to the aerobar extensions via a clamp ring or a bracket kit. Before buying, check whether the system is compatible with the diameter of your extensions. Bracket kits are available separately for systems that did not come with clamps as standard or for other extension diameters. BTA systems are placed between the extensions and must not disturb the position of the armrests: measure the free space between your extensions before you order.

Our advice: start with a torpedo drinking system of 500 ml if you do not know which volume you need. That is the most versatile format that suits most triathlon disciplines. Choose a version with a volume indicator if you take part in races: the indicator saves concentration on the course. Make sure that your bracket kit and straw are present for the first ride and keep a replacement straw at hand for longer races where the system is refilled several times.

Need help with your choice?

Would you like to buy a drinking system but you are not entirely sure which system best suits your wishes and needs? Then we are happy to help you further with all your questions. You can reach our triathlon specialists by phone on +31 (0)413-256800, send an email or visit our triathlon shop in Volkel, the Netherlands.

Frequently asked questions about drinking systems

What is the difference between a torpedo drinking system and an ordinary bottle cage?

A torpedo drinking system is an integrated hydration solution that you mount on the aerobar and where a straw or mouthpiece comes out directly in front of your mouth while you ride in time trial position. You do not have to take your hands off the supports to drink. An ordinary bottle cage on the frame holds a bottle that you have to take out of the cage by hand, which means that you have to sit upright for a moment or take your hand off the handlebar. On short rides that makes little difference, but on a triathlon bike leg of 90 kilometres a torpedo drinking system gives a practical advantage in ease and concentration.

Does a torpedo drinking system fit on every aerobar?

Most torpedo drinking systems are designed for extensions of a standard diameter and come with a bracket kit or attachment clamps. Most modern clip-on bars and aerobar extensions have a comparable diameter and are compatible. For some systems, separate bracket kits are available for extensions with a differing diameter or for attachment to the stem or a fork bridge. Before you order, check which attachment method the system uses and whether your aerobar has those mounting points. If you are in doubt, consult our specialists before purchasing.

How do I refill a torpedo drinking system during a race?

Most torpedo drinking systems have an opening at the top or a removable lid with which you can refill the reservoir. During a triathlon you usually do this in the transition zone or from a bottle that you take at a feed station. Some systems are designed so that you hold a bottle directly above the torpedo and pour it empty while you ride. Practise refilling at home or during a training session before you try it during a race: the action is simple but requires some practice to do quickly and without spilling in the riding position.

What is a BTA system?

BTA stands for Between-The-Arms: it describes the mounting position of the drinking system, namely between the aerobar extensions just in front of the rider's torso. It is the most used mounting position for triathlon drinking systems because the system thereby sits right in front of you, is easily reachable without changing position and is aerodynamically compact. BTS stands for Between-The-Stem and describes systems that are mounted lower and further forward, at the stem or the front fork. BTS systems have a flatter profile and a slightly different ride feel but work on the same principle.

Which volume do I choose for a half or full triathlon?

For a half triathlon with a bike leg of 90 kilometres, a torpedo drinking system of 500 ml is a good basic option. You ride on average one to one and a half hours on the bike and want to have at least 500 to 750 ml of fluid available. Combine the torpedo system with one or two bottles at the back of the saddle as a supplement. For a full triathlon with 180 kilometres of cycling, a larger system of 880 ml or a combination of two hydration points is more practical: you are on the bike for more than four hours and have to keep drinking consistently. During intensive effort, count on a fluid intake of 500 to 900 ml per hour depending on the temperature and your sweat level.