The Arundel Chrono II addresses the aerodynamic penalty that round bottles create in the bottom bracket area while meeting current UCI regulations for equipment legality. The system includes both the bottle and a dedicated cage designed to work together. The bottle shape fills the space behind the down tube more efficiently than standard round bottles, reducing the turbulence that happens when air moves around cylindrical objects at speed. This setup is specifically designed for the down tube position where the bottle sits in the airflow coming off the front wheel.

Arundel updated the Chrono II design after rule changes made the original Chrono configuration illegal for UCI-sanctioned events. The new bottle profile maintains aerodynamic benefits while conforming to regulations that govern bottle and cage dimensions. The cage has longer arms and more wrap compared to standard cages, which becomes necessary with the bottle's shaped profile. The extended arms distribute retention force across more surface area and prevent the bottle from working loose during riding. The cage holds the bottle firmly enough that you're not going to lose it on rough roads, but extraction still happens with a straightforward upward pull.

The bottle holds 17 ounces, which is smaller than standard 21 or 24 ounce bottles. This capacity works for criteriums, time trials, and shorter road races where you're prioritizing aerodynamics over hydration volume. If you're running the Chrono II on your down tube, you can still mount a standard bottle and cage on your seat tube for longer rides. Spare bottles are available separately, which matters if you want to pre-fill multiple bottles for races or if you damage a bottle and need a replacement.... Read More