Shimano RT-CL800 road and MTB bike brake disc with external nut

The 2 main areas of improvement targeted by the Shimano RT-CL800 disc are maintaining braking performance and better control of noise associated with overheating. It's a success!

With an exceptional level of silence, the RT-CL800 disc ensures your safety in all conditions of use and all terrains.

Problems of deformation caused by overheating have been virtually eliminated thanks to a new arm shape and optimised ventilation of the braking zone. The result is a clear improvement in braking performance and hitherto unrivalled silence.

For road use, we recommend 140mm front and rear for maximum weight savings and/or 160mm front/rear for optimum braking, or 160mm front and 140mm rear for a lighter, more efficient combination.

For MTB use, the diameter depends on your riding style.

This version of the disc comes with an externally tightened Centerlock nut.

Technical specifications

New ventilation concept
New shape
Heat dissipation Ice Technologies Freeza
CenterLock external clamping
With clamping nut
140, 160, 180 or 203mm
Weight: 96g in 140mm, 114g in 160mm

Questions & Answers

What is the Shimano RT-CL800 brake disc?

The Shimano RT-CL800 Disc Rotor is a top-of-the-range brake disc designed for road, gravel and mountain bikes. It uses Shimano Ice Technologies FREEZA technology to improve cooling and guarantee powerful, consistent braking, even on long descents.

What does the external nut version mean?

The external nut version means that the disc is fitted to the Center Lock hub with a lockring tightened by an external tool (such as a bottom bracket spanner). This version is often used when the hub axle or wheel design does not allow the use of an internal tool.

Which bikes is this disc compatible with?

The Shimano RT-CL800 Disc Rotor is compatible with :

road bikes

gravel bikes

MOUNTAIN BIKES

It is used with Center Lock hubs and is suitable for Shimano Ultegra, Shimano GRX and Shimano XT groupsets.

What disc sizes are available?

The disc is available in several diameters:

140 mm

160mm

180mm

203 mm

Sizes 140 and 160 mm are often used on road or gravel bikes, while 180 and 203 mm are more common on mountain bikes for more powerful braking.

What types of brake pads are compatible?

The Shimano RT-CL800 Disc Rotor is compatible with :

organic brake pads

sintered pads.

What are the advantages of Ice Technologies FREEZA technology?

This technology combines steel and aluminium in a sandwich structure to dissipate heat more efficiently.

The result is :

up to 50°C lower temperature

less downhill fading

longer pad life

more stable and silent braking.

Is the disc easy to install?

Yes, thanks to the Center Lock system, installation is quick and easy:

place the disc on the hub grooves

screw on the outer nut

tighten with the appropriate tool

This system is quicker and more rigid than discs with 6 screws.

Is the disc light?

Yes, the weight depends on the diameter:

~97 g (140 mm)

~114 g (160 mm)

~139 g (180 mm)

~169 g (203 mm)

This makes it a lightweight, high-performance disc for both road and mountain bikes.

What's in the pack?

The product generally includes :

1 disc Shimano RT-CL800 Disc Rotor

1 external Center Lock nut for fixing.

✅ In summary: the Shimano RT-CL800 Disc Rotor is a top-of-the-range, lightweight, high-performance brake disc, ideal for cyclists looking for powerful, consistent braking on road, gravel or mountain bikes.