Lightweight disc brake rotors

Here's some information I have collected on 180, 160 and 140mm lightweight disc brake rotors:

Disc brake rotor weightsWeight-180mm (g)Weight-160mm (g)Weight-140mm (g)Rotor Thickness (mm)Min Rotor Thickness (mm)Material

Scrub Components Raceday

Metal matrix / magnesium carrier
Carver Titanium

Scrub Components Workhorse635641

Metal matrix
NoTubes Coated Aluminium Rotor

Ashima Ai2

Stainless Steel

Ceramic coated aluminium
KCNC Razor957462

Stainless Steel
Gatorbrake Crown

Steel/Ti Coated
Alligator Aries10276

Stainless Steel, Titanium Nitride coating
Alligator Serration/Alligator Windcutter1047960.5

Stainless Steel
1.81.5Stainless Steel
Hope Race X2

Steel / Aluminium carrier
Ashima AiRotor ARO-0811285682.01.7Stainless Steel
R1 Formula rotor

Stainless Steel
Hope Tech X21538874

Steel/Aluminium carrier
Formula R1

Stainless Steel
A2Z Teppan Yaki SP5

Steel / Aluminium carrier
SRAM/Avid HS1 (2012)1349276

Stainless Steel
Magura Storm SL (2012)1229575

Stainless Steel
SRAM/Avid XX13396871.9
Stainless Steel
Carbon Ti

Steel/Carbon carrier
Alligator Starlite1289878

Stainless Steel
SRAM/Avid XX HSX (2012)12698881.9
Steel / Aluminium carrier
Avid G3 Cleansweep

Stainless Steel
Magura Marta SL

Stainless Steel
Hayes floating rotor

Steel / Aluminium carrier
Avid G2 Cleansweep

Stainless Steel
Shimano XT Ice Tech SM-RT86 6 bolt

SS/Alu Sandwich rotor/Alu carrier
12o'Clock Bikes

Steel / Aluminium carrier
Shimano XT RT75
2.01.5Stainless Steel
Shimano XT RT76152125

6-bolt versions, alu carrier/SS rotor
Shimano SM-RT51 *
2.01.5Stainless Steel

Note: the Shimano SM-RT51 rotor is obviously not "light-weight" but is included in the table for comparison purposes.

Some thoughts on the Scrub Components Metal Matrix Brake Rotors

The Scrub rotors are extremely expensive compared to other lightweight stainless steel rotors, but they are significantly lighter. However, you must use organic pads with these rotors and at present I don't know of any light weight pads that use a fully organic compound.

As a result the weight advantage from these rotors is offset by having to use heavier pads. For example:

RotorWeight (g)Brake Pad Weight (g)Total (g)
Scrub Components Workhorse561874
KCNC Razor74882
Weight difference-18+10-8

Lightweight brake rotor designs

The Hygia, Ashima AiRotor and KCNC Razor rotors, whilst being nice and lightweight, suffer from uneven rotor wear because the amount of material for the brake pads to rub against is different across the surface of the brake track.

To illustrate this point, take a look at the picture below. The two green lines indicate the extremities of the brake track and the red line shows roughly the middle of the brake track. If you follow the red line around you will notice that there is much less metal for the pads to rub against at this part of the rotor. This means, the metal that is there receives much more wear and so the rotor wears unevenly across the braking surface.

Hygia brake rotor with brake tracks marked

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Shimano XTR brake pad weights