Shimano RT-CL800 Center Lock 203mm Disc Brake Rotor

The Shimano RT-CL800 is an Ice Technologies Freeza rotor built to shed heat fast and keep braking consistent on long, steep descents. This 203mm version uses a Centerlock fitting with an internal-serration lockring and carries a built-in magnet that works with e-bike speed sensors, so it suits the front wheel of a road, gravel or e-bike build that needs both serious stopping power and accurate speed reading.

Highlights

Ice Technologies Freeza three-layer construction draws heat away from the braking surface for stable, fade-resistant performance
Built-in magnet for e-bike speed sensors, integrated into the rotor carrier
203mm diameter for maximum braking power, ideal for heavier loads and steep terrain
Centerlock mounting with an internal-serration lockring for fast, secure installation
Stainless steel braking surfaces over an aluminium core with exposed cooling fins
Ultegra/GRX-grade rotor, also cross-compatible with Shimano XT and other Centerlock systems
Ice Technologies Freeza cooling
The rotor sandwiches an aluminium layer between two stainless steel braking surfaces, with the aluminium extended into exposed radiator fins. This pulls heat out of the braking zone and lowers operating temperatures, which helps maintain braking force, extends pad life and reduces noise on sustained descents.

Built-in e-bike speed sensor magnet
Unlike the standard RT-CL800, this LJ variant has a magnet built into the rotor. It triggers the wheel-speed sensor on compatible e-bike systems, removing the need for a separate spoke magnet and giving a clean, accurate speed reading.