Magura Storm SL 6 Bolt Rotor
The Storm SL 6 Bolt Rotor is the lightest Magura brake rotor ever. To make it, Magura took the Storm rotor and gave it a serious diet to whittle away grams. The main change being the Storm SL has large, polygonal shaped vents and the Storm has smaller, round, drilled holes. The Magura Storm SL 6 Bolt Rotor comes standard on the Magura Marta brake but is a suitable lightweight replacement rotor for most disc brake calipers on the market regardless of manufacturer.
I have a 180 mm Storm SL rotor on an 29" Easton Wheel with a Shimano XT brake. It is light and works well. No complaints. I would buy it again.
These work better than most rotors I've ridden. Only occasionally get a squeal from the rear after it's been heated up. great modulation and heat dispersion.