The SEKA ExAero RDC is a true aero road bike. Built as a system to deliver tangible aerodynamic advantage and crisp, definite handling, regardless of frame size.
RDC stands for Racing Day Combatant. Same mould as the ExAero. Same geometry, same Wind Eye rear structure, same True-One-Piece Moulding, same Gladius ALTA cockpit included. The difference is the carbon schedule — and on an aero frame, where every gram of compensating material shows up in both weight and feel, that is where the performance gap lives.
Tested as a system, not as a frame
Most aero claims are component claims added together, as though airflow respects the boundary between a fork and a down tube. It doesn't. SEKA's programme with AeroCoach was built the other way round: frame, handlebar, bottles and rider integrated one variable at a time, across three full phases of wind tunnel testing, ending with a validation of the complete rider–bike system.
The headline number is therefore the bike as you actually ride it. A size 52 ExAero with the ALTA cockpit saves 6.14W over the Spear at 45km/h on conventional round bottles. Add the ExAero MAG magnetic aero bottle system and that becomes 11.63W — a 0.00992m² reduction in weighted CdA.
Bigger at the front, and faster for it
The instinct in aero design is to make every tube narrower, then add carbon back in to recover the stiffness that shaving lost — the rider pays twice, in weight and in a dead, unresponsive frame. SEKA went the other way. The ExAero keeps full structural depth in the head tube, fork crown, down tube and bottom bracket, and does the aerodynamic work by coordinating those sections with the cockpit so the front-end airflow is reorganised rather than merely squeezed. It presents 4.13% more frontal area than the Spear, and its system CdA still falls.
What the RDC carbon means
The layup pairs Toray T1100 with M46J high-modulus fibre, each doing a distinct job: T1100 handles the high-stress zones around the bottom bracket and head tube junction, while M46J controls deformation where the priority is holding shape under load rather than surviving a peak force. The RDC carries the more aggressive schedule in the areas where stiffness-to-weight decides the ride.
The result is 820g in size 54, excluding paint and metal components (±35g) — 115g under the standard ExAero — with 21.2% more front-end lateral stiffness and 13.4% more torsional stiffness than the Spear. The front-end figure is the one to feel for: it is steering precision, out of the saddle and holding a line at speed.
The ride
The Wind Eye — the open seatstay structure carried over from the Spear — allows up to 16mm of vertical movement at the seatpost while the rear end gains 7.6% in lateral stiffness. Nothing was traded for the stiffness gain: the same composure over broken surfaces, a firmer platform under power, and cleaner airflow through the most turbulent region on the bike. True-One-Piece Moulding forms the frame in a single mould, so pedalling loads never have to cross a bonded joint on their way through the head tube, bottom bracket or rear junctions.
The ALTA cockpit, and sizing down
Every ExAero frameset we sell is supplied with the Gladius ALTA. It raises stack by 25mm and holds reach exactly constant, which lets a rider drop a frame size and keep an identical position — same hands, hips and feet, less bike in the airstream. That is where the 6.14W comes from. Nineteen size combinations are available, with stems running 80–140mm across three width options. There is one caveat: sizing down is an aerodynamic strategy, not an automatic recommendation, and it's worth a fit conversation and a check for toe overlap before you commit — talk to us and we'll work it through with you.
Platform
Three phases of AeroCoach wind tunnel testing, 11.63W complete-system saving, Wind Eye compliance, T1100/M46J layup, True-One-Piece Moulding, SRAM UDH hanger, 32mm tyre clearance and seven sizes on a fixed 408mm chainstay — as detailed on the [ExAero Collection page [COLLECTION LINK]].