Open Back High Side EVO Arm Cups: Locked-In Support with High-Wall Stability

The TriRig Open Back High Side EVO Arm Cups are designed for athletes who want a more secure and supportive aero position without adding unnecessary bulk. Built from carbon fiber and shaped with an ergonomic 3D-tapered profile, these cups deliver a locked-in feel with a slim, performance-oriented design.

Featuring a high-wall construction and open-back layout, the EVO cups increase arm wrap and surface contact to improve stability and reduce unwanted movement in the aero position. With a medium-snug 95mm arc diameter, they provide a comfortable fit for a wide range of riders while maintaining excellent support over long efforts. Weighing just 535 grams per pair, they balance stiffness, comfort, and lightweight performance.

Open Back EVO Arm Cups

• Length: 201 mm
• Internal Width: 95 mm
• Internal Depth: 76 mm
• Side Wall Height: 36 mm
• Weight: 535 g per pair
• Horizontal Mounting Hole Spacing: 15.5 mm
• Vertical Mounting Hole Spacing: 20 mm

Designed for easy adjustability, the Open Back High Side EVO Arm Cups use a versatile 3×5 bolt hole pattern with elongated mounting slots to maximize fit options. This allows riders to fine-tune reach, width, and positioning for both aggressive race setups and endurance-focused comfort. Their carbon fiber construction ensures durability while keeping a clean, low-profile look.

The Open Back High Side EVO Arm Cups offer a significant ergonomic upgrade for athletes seeking better arm support, improved fit customization, and a more stable aero position—so you can stay comfortable, confident, and focused when it counts.