Shimano Dura-Ace RT-CL900 Centrelock Disc Brake Rotor (External Serration)

$84.99 AUD

Taxes included. Shipping calculated at checkout.

The Shimano Dura-Ace RT-CL900 External Serration Centrelock Disc Brake Rotor is a premium road and gravel disc rotor engineered for quieter braking, excellent heat management and consistent stopping power.

RT-CL900 Features

Premium Shimano Dura-Ace-level Centrelock disc rotor for road and gravel bikes
Ice Technologies Freeza construction helps reduce heat build-up and brake fade
External serration lockring design suited to many modern thru-axle disc wheelsets
Updated robust rotor arm shape reduces vibration, heat deformation and brake noise
Available in popular 140mm and 160mm road disc brake sizes

(more details...)

Technical Specifications

Product Name: Shimano Dura-Ace RT-CL900 External Serration Centrelock Disc Brake Rotor
Model: RT-CL900
Series: Shimano Dura-Ace / Shimano Centrelock Ice Technologies Freeza
Rotor Mount Type: Centrelock
Lockring Type: External serration
Brake Type: Disc brake
Common Road Sizes: 140mm and 160mm
Manufacturer Rotor Size Range: 140mm, 160mm, 180mm, 203mm
Average Weight:140mm: approximately 97g160mm: approximately 114g180mm: approximately 139g203mm: approximately 169g
Rotor Construction: Stainless steel / aluminium / stainless steel sandwich construction
Carrier: 3D-shaped aluminium carrier
Cooling Technology: Shimano Ice Technologies Freeza
Heat Management: Heat dissipation paint and exposed aluminium radiator fins
Pad Compatibility: Shimano narrow road pad lining shape; compatible with suitable Shimano resin or metal disc brake pads depending on caliper setup
Hub Compatibility: Centrelock-compatible hubs
Bike Compatibility: Road bikes, aero road bikes, endurance road bikes, gravel bikes and performance disc brake bikes
Recommended Use: Road racing, endurance cycling, gravel riding, Gran Fondo events, fast bunch rides, climbing routes and technical descents
Colour: Shimano Dura-Ace silver / black finish
Installation Tool: External Centrelock bottom bracket-style lockring tool
Included Items: Rotor and lockring depending on retailer packaging

Compatibility Notes

External serration lockrings are commonly used on modern thru-axle road and gravel wheelsets where external tool access is suitable.
Designed for Centrelock hubs only.
Not directly compatible with 6-bolt hubs unless using a suitable adaptor.

Ice Technologies Freeza Cooling

The RT-CL900 uses Shimano’s Ice Technologies Freeza construction to improve heat dissipation during sustained braking. This is particularly useful on long descents, repeated braking efforts and high-speed road riding where heat build-up can cause brake fade, rotor noise or pad rub.

Three-Layer Rotor Structure

The rotor uses a stainless steel / aluminium / stainless steel sandwich construction. The stainless steel outer braking surfaces provide braking durability, while the aluminium core helps draw heat away from the braking track.

Heat Dissipation Paint

Shimano applies heat dissipation paint to the cooling fins to further support temperature control. Better heat management helps maintain a more consistent braking feel during demanding rides.

3D Aluminium Carrier

The optimised 3D-shaped aluminium carrier is designed for low weight, stiffness and heat distortion resistance. This helps reduce rotor deformation and improves braking consistency under heavy loads.

Updated Arm Shape

The revised rotor arm profile improves rigidity and helps reduce vibration. This contributes to quieter braking, smoother modulation and reduced rubbing noise compared with older rotor designs.

Centrelock Mounting System

Shimano’s Centrelock system uses a splined rotor interface and lockring for fast, secure installation. Compared with 6-bolt systems, Centrelock can simplify rotor fitting, removal and ongoing bike maintenance.

External Serration Lockring Advantage

The external serration lockring is especially practical for many modern thru-axle hubs because it uses a bottom bracket-style tool interface.

Available Rotor Sizes

140mm

Lightweight option for road race bikes
Common rear rotor size
Suitable for lighter riders, flatter terrain and riders prioritising low weight

160mm

Popular front rotor size for road and gravel bikes
Offers stronger braking power and better heat management than 140mm
Recommended for heavier riders, steep descents, endurance riding and mixed conditions

Best Suited For

Road racers
Performance road cyclists
Endurance riders
Gravel riders
Shimano Dura-Ace, Ultegra and 105 hydraulic disc brake users
Riders upgrading from entry-level Shimano rotors
Cyclists replacing worn, noisy or heat-warped rotors

Gravel Cyclist, June 2022, highlighted Shimano’s focus on reducing heat deformation and brake noise with the RT-CL900 and RT-CL800 rotor platform, particularly through Ice Technologies Freeza cooling and improved carrier design.

Hands On Bike, April 2024, compared the RT-CL900 with earlier Shimano Dura-Ace and XTR rotors, noting the updated carrier design, improved cooling fin layout and focus on reducing heat-related rotor warping.

Overall professional feedback positions the RT-CL900 as a premium rotor for riders who want Shimano’s best balance of braking performance, heat control, low weight and quieter operation.

Gravel Cyclist, June 2022, highlighted Shimano’s focus on reducing heat deformation and brake noise with the RT-CL900 and RT-CL800 rotor platform, particularly through Ice Technologies Freeza cooling and improved carrier design.

Hands On Bike, April 2024, compared the RT-CL900 with earlier Shimano Dura-Ace and XTR rotors, noting the updated carrier design, improved cooling fin layout and focus on reducing heat-related rotor warping.

Overall professional feedback positions the RT-CL900 as a premium rotor for riders who want Shimano’s best balance of braking performance, heat control, low weight and quieter operation.