Shimano Dura-Ace (RT-CL900) vs XTR (RT-MT900) Rotors Comparison

Founder, Mr. Mamil

Ever wondered about the differences between the Shimano Dura-Ace (RT-CL900) and XTR (RT-MT900) disc brake rotors?

Drawing from my experience using these rotors and detailed research, I’ll compare these top-of-the-line Shimano rotors, highlighting the differences in design, performance characteristics, applications, and advantages.

Shimano rotor models

The Shimano Dura-Ace and XTR rotors have 900 at the end, indicating they’re Shimano’s top-of-the-line disc rotors. Pay attention to the letters before the 900.

The table below shows all the available Shimano Dura-Ace and XTR rotors. All three rotors are cross-compatible with each other.

Model no.SeriesUse
RT-CL900Dura-Ace R9200 (12-speed)Road cycling
SM-RT900Dura-Ace R9100 (11-speed)Road cycling
RT-MT900XTR (12-speed)Mountain biking
Shimano Dura-Ace and XTR rotor models

Rotor design

Shimano XTR vs Dura-Ace Rotors
Shimano Dura-Ace 12-speed (L), Dura-Ace 11-speed (C), and XTR (R) Rotors

The rotors use the Shimano ICE and Freeza Technologies for efficient heat dissipation. The main difference lies in their design.

Dura-Ace rotor design (RT-CL900, SM-RT900)

Both Dura-Ace rotors have four arms that curve with the wheel rotation connecting to the braking surface.

The Dura-Ace RT-CL900 rotor only has cooling fins where needed most, with larger gaps between the fins and arms. With this design, the cooling and heat dissipation may be slightly compromised, but generally, this is not an issue as the disc brakes aren’t designed to be continuously dragged down a descent. 

On the other hand, the Dura-Ace SM-RT900 rotor has larger cooling fins, making them look more solid and aero.

XTR rotor design (RT-MT900)

The XTR rotor has four arms at a 90º angle for 140mm and 160mm size and five arms for 180mm and 203mm rotors to provide additional strength.

The cooling fins are placed where needed most, with larger gaps between the fins and arms.

Braking performance

With the difference in rotor designs, many cyclists claimed that the XTR rotors (RT-MT900) have a slight edge in braking performance. The pros use them on the long and steep descends in the Tour de France, where the braking performance is tested to its limits. 

Besides that, many cyclists also assumed they should perform better because they’re designed for mountain bikes.

From my experience of using all three rotor models, quantifying these is hard. The fact that Shimano updated the Dura-Ace (RT-CL900) to resemble the XTR rotor (RT-MT900) indicates that there is some truth in what many cyclists claim,

Rotor weight and sizes

One of the main reasons cyclists, especially the weight weenies, prefer the XTR rotors is because it’s lighter.

Both the Dura-Ace rotors (RT-CL900 and SM-RT900) have the same overall weight of 210g with a 160mm front and 140mm rear combination. The Dura-Ace rotors are available in 140mm and 160mm sizes.

The XTR rotors (RT-MT900) are available in 140, 160, 180, and 203mm. The 180 and 203mm rotors will not fit onto a road bike.

A road bike with a 160mm front and 140mm rear rotor could save up to 20g just by switching to XTR rotors.

SeriesModel no.Rotor sizeWeight
Dura-Ace (12-speed)RT-CL900140mm96g
Dura-Ace (12-speed)RT-CL900140mm114g
Dura-Ace (11-speed)SM-RT900140mm94g
Dura-Ace (11-speed)SM-RT900160mm116g
Shimano Dura-Ace and XTR rotor weight comparison

What are the similarities between these rotors?

Shimano ICE Freeza Technology
Shimano ICE Freeze Technologies Explained

We’ve discussed the differences, but there are also some similarities between them that you should also know about.

  • Shimano’s top-of-the-line rotors. The Dura-Ace is for road bikes, and XTR is for mountain bikes, although they’re cross-compatible.
  • ICE Freeza Technologies is Shimano’s latest technology to cool down the rotors for consistent performance, especially during hard braking. The rotors have a three-layer sandwich structure; stainless steel, aluminum, and stainless steel. The Freeza is where the aluminum extends into the cooling fins for better heat dissipation.
  • Centerlock (AFS). Both are Centerlock rotors and will fit all of the disc brake wheelsets. Older wheels that use a 6-bolt pattern will need an additional adapter.
  • Brake pads. They work with Shimano’s and other third-party road bike brake pads for the R9200, R9170, R8100, and R8070 calipers. Brake pad compatibility is the function of the brake calipers, not the rotors.

Pricing and availability

Pricing-wise, the Dura-Ace and XTR rotors differ between $5 to $10.

The challenge many cyclists face is the availability of the XTR 140mm rotors, which are hard to come by since not many mountain bikes use them.

SeriesRotor sizeRetail price (USD)Available at
Dura-Ace (RT-CL900)140mm$86Amazon
Dura-Ace (RT-CL900)140mm$86Amazon
Dura-Ace (SM-RT900)140mm$82Amazon
Dura-Ace (SM-RT900)160mm$82Amazon
XTR (RT-MT900)140mm$80Amazon
XTR (RT-MT900)160mm$80Amazon
XTR (RT-MT900)180mm$85Amazon
XTR (RT-MT900)203mm$85Amazon
Shimano Dura-Ace and XTR rotor pricing and availability

Shimano disc rotors FAQ

What is the difference between RT-MT800 vs RT-MT900 rotors?

What is the difference between RT-CL800 vs RT-CL900 rotors?

Alex Lee at Mr.Mamil

Alex Lee is the founder and editor-at-large of Mr. Mamil. Coming from a professional engineering background, he breaks down technical cycling nuances into an easy-to-understand and digestible format here.

He has been riding road bikes actively for the past 12 years and started racing competitively in the senior category during the summer recently.