Along with the custom adjustments I am making for my cockpit on my time trial bike I am embracing the current trends and am adding a between the arms (BTA) bottle system to my setup. One of my main issues with this system is how expensive most products on the market currently are, with only a few companies making bottles for BTA setups. Something that would be nice to have and is similar to what many companies have as an add on, which required the purchase of a proprietary set up are BTA bottles that have a tube that runs up the arm rests to make it easier for the rider to drink from.
As shown in the image on the left, companies like WattShop have a set up that uses traditional cycling bottles and bottle cages. The whole point of this design is to be more aerodynamic, but if the rider is having to come out of the aero position to drink from their bottle it defeats the purpose. That is why many systems have a straw or bite-valve that reaches up to the athlete’s mouth, allowing the rider to maintain their position while hydrating. The system that Vision uses, as shown below, is nice and simple as it is an all in one system that is able to be fully optimized for a given cockpit, many companies, like Trek, who have thier own component brands do something similar. When comparing the system from WattShop to the proprietary ones from Vision or Trek the design WattShop uses allows any water bottle to be used, but doesn't have the tube that makes the positioning and benefits of the BTA system so beneficial.
Some manufacturers have even introduced a multi bottle system which is useful for increasing capacity, but these assemblies invariably require proprietary bottle profiles and custom mounting hardware as they are less likely to fit standard equipment. Moreover, despite claims of superior aerodynamics, these multi-bottle systems will inevitably increase frontal area, shift weight on the handlebars which create handling issues, as well as just being more in the rider’s way. As mentioned earlier, these multi-bottle systems are additionally difficult to use while staying tucked in an aero position since the additional bottles are harder to reach.
To add another layer of complexity, the ITU has recently added equipment regulations regarding hydration limits, directly impacting BTA systems. The rule added in 2025 limits front-mounted systems to carrying a maximum of 2 bottles, each limited to a max volume of 1 Liter. These rules aim to standardize allowable fluid volume and curb exotic rigs, and dangerous configurations that limit rider position and mobility.
This has led me to the design that I have been working on. The goal is to bridge the gap between the two styles by making an easily swappable lid that fits on any bottle with a straw for the racer. This would allow fo the benefits of both systems, and allow the rider to quickly change bottles mid race, limiting the number of bottles they need to carry to fit with the ITU's rules.