FAQs / Bicycle Components / Brakes / Lightweight disc brake rotors

FAQs - Brakes

Lightweight disc brake rotors

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

Disc brake rotor weights	Weight-180mm (g)	Weight-160mm (g)	Weight-140mm (g)	Rotor Thickness (mm)	Min Rotor Thickness (mm)	Material
Innolite		48				Aluminium
Scrub Components Raceday		50	39			Metal matrix / magnesium carrier
Carver Titanium		55	45			Titanium
Scrub Components Workhorse	63	56	41			Metal matrix
NoTubes Coated Aluminium Rotor		57				Aluminium
Ashima Ai2		66				Stainless Steel
Ceradure	85	72	59			Ceramic coated aluminium
KCNC Razor	95	74	62			Stainless Steel
Gatorbrake Crown		76				Steel/Ti Coated
Alligator Aries	102	76				Stainless Steel, Titanium Nitride coating
Alligator Serration/Alligator Windcutter	104	79	60.5			Stainless Steel
Hygia		80		1.8	1.5	Stainless Steel
Hope Race X2		80	65			Steel / Aluminium carrier
Ashima AiRotor ARO-08	112	85	68	2.0	1.7	Stainless Steel
R1 Formula rotor		87				Stainless Steel
Hope Tech X2	153	88	74			Steel/Aluminium carrier
Formula R1		89				Stainless Steel
A2Z Teppan Yaki SP5		89				Steel / Aluminium carrier
SRAM/Avid HS1 (2012)	134	92	76			Stainless Steel
Magura Storm SL (2012)	122	95	75			Stainless Steel
SRAM/Avid XX	133	96	87	1.9		Stainless Steel
Carbon Ti		98				Steel/Carbon carrier
Alligator Starlite	128	98	78			Stainless Steel
SRAM/Avid XX HSX (2012)	126	98	88	1.9		Steel / Aluminium carrier
Avid G3 Cleansweep		102				Stainless Steel
Magura Marta SL		105				Stainless Steel
Hayes floating rotor		114				Steel / Aluminium carrier
Avid G2 Cleansweep		114				Stainless Steel
12o'Clock Bikes		116				Steel / Aluminium carrier
Shimano XT RT75		125		2.0	1.5	Stainless Steel
Shimano XT Ice Tech SM-RT86 6 bolt		129				SS/Alu Sandwich rotor/Alu carrier
Shimano SM-RT51 *		145		2.0	1.5	Stainless Steel

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

Some thoughs 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:

Rotor	Weight (g)	Brake Pad Weight (g)	Total (g)
Scrub Components Workhorse	56	18	74
KCNC Razor	74	8	82
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.