Shimano Dura-Ace WH-R9270 C50 Disc Carbon Tubular 700c Rear Wheel

WH-R9270 TL carbon clincher disc brake designed to meet pro road race criteria.

Expect to see the new Dura-Ace C50 tubular wheels under top professionals on most days of racing. With an ideal balance of lightweight materials and aerodynamic efficiency, the 50 mm rim and new hub design are always a good racing option.

The new Dura-Ace C50 tubular wheel offers the aerodynamics of a deeper wheel with the weight of a shallower one. In other words, the C50 tubular is the ideal balance of performance whether you're in the pro peloton or a weekend group ride.

C50 - All Rounder

An all-round model that focuses on classic races with intense up-and-down and solo escapes.

Fast, easy to handle, and light. A versatile model that has aerodynamic performance comparable to that of C60 but can also easily climb slopes with a weight close to that of C36.

Focusing on races with intense ups and downs, the model was designed to offer riders an advantage in various situations that are directly linked to victory or defeat. Such situations include a powerful attack on a short steep slope, a technical downhill with many corners, and escaping from opponents. C50 is the best all-round wheel in Shimano’s history, Shimano's recommendation for all riders.

Technology

D2

Aerodynamic performance is affected by wind direction. To create the D2 rim, Shimano engineers considered both frontal and cross winds, aiming to achieve optimal performance in real-world riding conditions. Extensive prototype testing, in the wind-tunnel and on the road, proved that a wide rim shape with a deep tire bed performs best across a wide range of conditions. At yaw angles ranging from 0 to 15 degrees, the Shimano D2 rim profile reduces air drag better than others aero shape rims. This rim design also boosts lateral wheel stiffness and offers improved vertical compliance for increased control, comfort and durability on the road.

Compared to the conventional product C40-TL, air resistance has been reduced at all yaw angles on C36-TL, which has about the same rim height. In the conversion method that considers the direction of the winds received under actual running conditions, the drag has been reduced by about 3 W. Of course, air resistance has been further reduced on both C50-TL and C60-HR-TL.

OPTBAL

The OPTBAL rear wheel spoke system features 21 spokes—14 on the drive side and 7 on the non-drive side. Cassette spacing in today’s wheels produces unbalanced tension in traditional 1:1 spoke systems. This unbalance is intensified with the 11-speed cassette, producing nearly double the tension on the drive side spokes. Generally high and low tension spokes have respectively tendency toward breaking down and coming loose spoke nipples. Unbalanced tension affects durability and strength. The OPTBAL design rebalances spoke tension, enhancing wheel rigidity and strength for a more durable wheel.

Science of Speed

Wheel performance is determined by three factors: aerodynamics, rigidity, and weight.

The new Shimano Road wheel collection optimizes the balance of those characteristics based on specific applications like climbing, all-round performance, or high-speed scenarios. Wheels unlike any other.

Decomposition of acceleration performance

To develop a wheel that advances crisply, responding to the rider’s pedalling force, that is, a wheel with excellent acceleration performance, Shimano made efforts to achieve two elements: improvement of drive rigidity and reduction of energy required for acceleration.

Drive rigidity

Shimano succeeded in dramatically increasing the drive rigidity compared to that of a conventional model.

Compared to the conventional product C40-TL, the drive rigidity has improved by 63% on C36-TL, by 69% on C50-TL, and surprisingly by 89% on C60-HR-TL (high-rigidity specification).

Decrease of energy required for acceleration

Compared to the conventional product C40-TL, the energy required for acceleration has been reduced by 12% on C36-TL, by 10% on C50-TL, and by 6% on C60-HR-TL.

Centre Lock

The Centre Lock system makes an easy rotor installation possible with spline mount and a lock ring. The lock ring mounting system reduces the total working hours by shortening the amount of time of both installation and de-installation. In addition, the secure fixing by the spline mount enhances precision and rigidity while improving braking efficiency.

E-Thru

The tool-less type thru-axle skewer system optimizes rigidity and weight balance and enables easy operation with a reliable internal cam mechanism. The 15mm thru-axle system is 15% stiffer torsionally and 25% stiffer in transverse shear than a traditional 9mm quick release front axle system. High rigidity is secured while keeping the optimum weight balance. The E-Thru axle hub system minimizes the distortion of suspension while maintaining lightweight for riding around sharp corners at high speed.

Features

• Lightweight tubular full carbon 50mm deep rim for improved aerodynamics, increased rigidity and excellent inertia for sprinters and TT specialists
• Easy to use Center Lock rotor mount for use with disc brakes
• Stainless steel butted (2.0-1.8-2.0) and bladed straight pull spokes for optimal balance and rigidity
• Elbow-less spokes make for a strong yet compliant wheel
• High lateral rigidity is produced with a wide flange spacing
• Labyrinth double-contact sealing effectively shuts out water and dirt
• Alloy cone with integrated steel Borozon treated bearing races - super mirror finish reduces friction
• Cold forged, machined aluminium hub shell and oversized 7075 alloy axle keep the wheel weight to a minimum
• For 142 x 12mm axle
• 700c tubular compatible