CeramicSpeed OSPW Aero Alpha V3 SRAM Red AXS D1/E1 and Force AXS D1

The CeramicSpeed OSPW Aero Alpha V3 SRAM Red AXS D1/E1 and Force AXS D1 is an oversized pulley wheel system that replaces the stock pulleys and cage on SRAM's wireless road derailleurs. It has two jobs: cut the friction in your rear derailleur and cut the drag it creates in the wind. It uses 15-tooth and 19-tooth pulley wheels on low-friction, hand-built bearings. CeramicSpeed says this setup reduces friction by 35 to 40 percent compared with a stock pulley configuration.

The aero side of the Aero Alpha came from wind tunnel work. CeramicSpeed developed the cage structure over two years with Simon Smart, founder of Drag2Zero, who moved into cycling in 2007 after a background in Formula One. In CeramicSpeed's testing, the OSPW Aero reduces drag locally by 40 percent on average compared with a stock derailleur, and by up to 60 percent at some points. Smart himself is realistic about the scale: the rear derailleur is only about 1 percent of total system drag. Even so, it's one of the most awkward areas of the bike to get airflow right, so a small, measurable gain here is the kind of marginal improvement that matters to time trialists and triathletes.

ALPHA Disc and Active Debris Remover

The Alpha name refers to the ALPHA Disc pulley design. Each pulley wheel is two pieces: a narrow-wide tooth profile in a composite material that resists wear and keeps the drivetrain quieter, and a solid aluminum disc that adds strength and stiffness. The solid disc also stops foreign objects from lodging between pulley spokes and smooths the airflow around the pulley.

Bearing protection comes from CeramicSpeed's Active Debris Remover. A dust cover sits in a groove in the pulley wheel and fully encloses the bearing. A bladed groove structure around it actively moves debris out as the pulley turns. CeramicSpeed developed it in lab and real-world testing, and the aim is to keep dirt out of a bearing that is meant to stay fast.

What's new in V3

V3 adds a revised cage interface shared with CeramicSpeed's OSPW RS Alpha platform. The change is to the installation: CeramicSpeed says it makes fitting faster, easier and more consistent, with the same aerodynamic benefits, efficiency and durability as the earlier Aero Alpha. The system fits SRAM Red AXS D1/E1 and Force AXS D1 rear derailleurs. Check the CeramicSpeed compatibility matrix for any other SRAM derailleur before ordering.

Every pulley, cage and bearing is produced and assembled by hand in Denmark. The kit comes with 15 ml of UFO Tech bearing oil, a CeramicSpeed decal, a SRAM AXS cage tool and a D-shaped washer. It is built for road and triathlon bikes, and it suits riders who care about drivetrain efficiency and want every aerodynamic and friction gain available.