Open Back High Side EVO Arm Cups

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.

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.

TriRig designs innovative, aerodynamic products built with elite athletes and proven through real-world performance. With a relentless focus on progress, problem-solving, and minimal design, every product helps athletes push limits and achieve their personal best.

• Lightweight Carbon Design: Carbon fiber construction delivers excellent stiffness and support while keeping overall weight low for race-ready performance.
• Ergonomic Support: The high-wall, open-back shape increases arm wrap and surface contact to improve comfort and reduce fatigue during long rides.
• Open Back Profile: Provides a more natural arm position with added stability while allowing easier entry and exit from the cups.
• Extended Adjustment Range: Features a versatile 3×5 hole pattern with elongated mounting slots to accommodate a wide range of fit and positioning setups.
• Medium-Snug Fit: Designed around a 95mm arc diameter for a secure, supportive fit across a wide range of rider anatomies.

• ⚙️Compatibility: Scoops mount using two fore/aft bolts into matching threaded bosses on your arm-pad bracket/aerobar. Check that your bracket’s hole pattern aligns; both bolts must be used for a safe, stable install. Non-standard patterns may require Wingspan Extenders.
• Fits most aerobars on the market, including Alpha One/Alpha Prime.
• Comes with M5 and M6 bolts for easy installation.
• 🔧 Need help with the install? See our install guide.

Orders start processing fast!  We aim to have orders, placed before noon MT on business days (non-holiday Mondays through Fridays), leave the warehouse that same day. Orders placed after noon (MT) on a business day, or on a weekend, will ship the following business day. 

TriRig ships most packages via OSM / USPS and FedEx although we may change these at any time. 

📦 Shipping Insurance:

To add piece of mind to your order, we offer shipping insurance (Checkout+) for domestic and international customers. Checkout+ is a completely optional shipping protection that helps resolve carrier-related delivery issues more quickly. (This service is also combined with free returns). 

⭐What Checkout+ covers:

• Packages that are lost or mis-delivered by the carrier

• Faster replacement or refund without waiting for a carrier investigation to complete

• Coverage applies when the correct shipping address is entered at checkout

❌What Checkout+ does not cover:

• Incorrect or incomplete addresses entered at checkout

• Address changes after an order has shipped

• Packages delivered to the address provided during checkout

• Delays or delivery issues caused by customer moves, temporary addresses, or expired delivery locations

***Checkout+ does not override customer responsibility for entering a valid, accurate shipping address.

🌍 International Shipping & Import Fees

• We ship anywhere in the world! 

• International orders may be subject to VAT, duties, import taxes, and carrier handling fees

• These charges are assessed by the destination country and are the customer’s responsibility

• TriRig does not collect or reimburse import taxes or VAT unless explicitly stated at checkout

⚠️ We are not responsible for delivery delays, holds, or returns caused by unpaid duties, taxes, or customs clearance issues.

• All returns, exchanges and claims are handled through our self serve portal.
• Items may be returned within 30 days of the original purchase date.
• Item must be in brand new condition, uninstalled with no blemishes and complete with all original materials and packaging.
• Item must be in resell-able/re-stockable condition.
• ⭐With Checkout+: Fee returns and return shipping.
• ❌Without Checkout+: All returns will be subject to a 15% restocking fee.
• We reserve the right to deny any returns who do not meet the return conditions above. 
• If an individual item lists a deviation from this policy (such as no returns), then that deviation applies, and supersedes this return policy.
• International returns: Accepted on a case by case basis. We do not provide return labels for international returns. Orders unprotected by checkout+ are subject to a 15% restocking fee. 
• Limited warranty is valid for 1 year after purchase date. 
• Extended warranty (purchased with Redo) is valid for 2 years after purchase date.
• For more information on our warranty policy, visit our Warranty Policy page.