Grappler Sidekick Flux GR Enduro Aluminum Wheels are a groundbreaking revolution in MTB, at an incredible value. Tested over multiple World Cup seasons by the world's fastest athletes, these wheels consistently deliver top results. Second-generation Sidekick J-bend hubs feature a wider 9°/13°/18° adjustable deadband that eliminates pedal kickback, enhancing suspension performance and filtering drivetrain shock and vibration before it reaches the rider. A magnetic pawl-retraction system, combined with new bearings and seals, reduces drag, making these the fastest-rolling wheels e*thirteen has ever made. Low-profile Flux Aluminum rims set new standards in compliance, strength, weight, and performance. Flux 55 Aluminum rims provide exceptional durability and ample compliance in 29" front and rear wheels. 27.5" rear wheels are built with burlier Flux 66 GR rims to withstand the added abuse of mixed-wheel gravity use. Together, these technological marvels offer increased comfort, enhanced speed and control, and a lively ride feel that won't disappoint. Efficient, predictable suspension performance, added traction and tracking, reduced rider fatigue, and nearly silent hub operation create a more confident and immersive ride experience for both pros and enthusiasts. Rear-tuned build: Drive-side stiffness and reinforced lacing deliver crisp power transfer with minimal flex when you load the rear wheel. Freehub options to match your drivetrain: Choose HG, XD or Microspline. Sidekick anti-kickback hub technology eliminates kickback and filters drivetrain vibration, improving ride feel and suspension performance. Enhanced comfort and control: Ultra-compliant, low-profile Flux Aluminum rims add radial compliance and traction without reducing steering precision and feel. Lightweight , durable Flux 55 rims provide ample compliance, bump absorption, and traction in front and rear 29" wheels, while more robust Flux 66 GR rims are used in 27.5" rear wheels for added toughness. Free speed: Sidekick hubs have exceptionally low drag and whisper-quiet operation, carrying more speed than other freehub systems. Lively ride feel: The low profile height combined with a double-butted 28-spoke build makes for a responsive, dynamic ride. Handbuilt to exacting precision with AL 6069 welded rims, double-butted spokes, and locking brass nipples, for ultimate performance and longevity. *Tubeless valves not included