Description The Apidura Aero System is a racing frame bag & top tube bag combination designed to be as aero-dynamic as possible. The Aero System is a performance-oriented solution for competitive gravel racers, developed through rigorous Computational Fluid Dynamics (CFD) analysis. With an average 5 watt saving at race speed, it’s wind tunnel tested and race-proven at the highest level, showing a benefit on every bike Apidura tested. The Aero System was designed with the primary purpose of improving aerodynamic performance, regardless of what you decide to pack. Apidura Aero System Features FRAME INTEGRATION – Downtube Transfer Panels optimise aerodynamics. An upper skirt minimises gaps around the top tube STEM INTEGRATION – Top Tube Module has Transfer Panels designed to conform to the stem for aero-optimised integration QUICK ENTRY TOP TUBE MODULE – Magnetic opening allows for quick, one-handed access to Top Tube Module SECURE ZIP CLOSURE – Frame Module uses a secure zip for safely storing heavier or bulkier items MADE FROM HEXAGRID – Ultralight, high-strength nylon grid, laminated with TPU for a minimalist, yet structured material STURDY ATTACHMENT – Velcro strap secures to downtube whilst low profile Tension Bands attach around headtube HYPALON LOAD STRAPS – Backed with silicone to increase grip and featuring a cam lock system for added security NON-SLIP SILICONE LINING – Modules are backed with silicone to create grip and prevent unwanted movement KNEE CLEARANCE – Slim profile reduces chance of knee rub when sprinting CABLE PORT – Enables charging of devices on the go Sizing Advice from Apidura: The Aero System is designed to integrate with your bike to deliver an aerodynamic benefit. As such, the available sizes relate not to the capacity, but to the size of bike that is best suited to deliver this benefit. We recommend using our Frame Pack Sizing Tool to check the fit before purchase. As a rough guide, the L/XL size is best suited to bikes sized 56-58cm and above. The S/M is best matched to bike sizes from 52-56cm.