Aprilia’s recent patent reveals new structural details featuring carbon-fibre & aluminium frame

Aprilia, an Italian motorcycle and scooter manufacturer known for its high-end superbikes, naked bikes, adventure bikes, and streetfighters, has been experimenting with a carbon fibre frame for its RS-GP MotoGP race bike since 2023. As per the information, a recent patent application from parent company Piaggio reveals new structural details of the latest RS-GP prototype chassis, which combines carbon fibre and aluminium bonded with adhesive rather than bolts.

Image Source: Aprilia website

Use of aluminium & carbon fibre

Aprilia has been actively testing carbon frames on its MotoGP bikes throughout 2023 and 2024, though it has yet to commit to using them in competition. The swingarm pivot area is primarily aluminium, with two cast components labelled "4R" and "4L" in the patent drawings. The carbon frame's outer skin extends over these castings, creating a large bonding surface to glue the parts together securely.

Although Aprilia tested its carbon MotoGP chassis in late 2023 and continued development through 2024, the 2025 race bike still relies on an aluminium frame — though the swingarm is made entirely of carbon. This could change in the future if Aprilia's ongoing research into carbon frame technology delivers the right performance gains.

While carbon fibre has been the material of choice for top-level racing cars for over 40 years, it remains a contentious option for motorcycle frames, with teams still weighing the balance between its benefits and challenges.

Aprilia isn't the only manufacturer exploring carbon fibre frames. KTM has recently tested a carbon frame, and several GP bikes — including Aprilia's — already feature carbon swingarms. Ducati even raced with a carbon monocoque frame from 2009 to 2011, securing multiple victories before reverting to a more conventional aluminium design mid-season 2011.

About the patent

The patent documents reveal that the front section of the frame is primarily carbon fibre, including the steering head, with metal bushings embedded at the top and bottom for the steering shaft. The steering tube has an oval cross-section, enhancing aerodynamics compared to a traditional circular shape.

It's moulded as a single piece with the frame's side rails but connected to them only by narrow sections at the top and bottom, leaving large openings on either side to channel air from the bike's nose intake into the airbox. The side frame members consist of an outer carbon skin with a separate inner skin bonded in place, forming hollow beams reinforced by hidden internal braces.