AbsoluteBlack has introduced what they claim is the lightest CenterLock rotor in the world. The Raven SL uses FEA analysis, extensive heat treatment and a two-piece design to tip the scales at just 95g for a 160mm rotor.
By comparison, Shimano’s IceTech XTR’s 160 comes in at a claimed 160g. That weight is possibly including their lock ring, which AB’s weight does not, but it’s still an impressive gram drop.
The weight savings are just the beginning, though. AbsoluteBlack’s rotors use some serious top shelf materials, and the outer friction ring is replaceable, making the upgrade cost more bearable knowing you can replace a worn rotor fairly inexpensively.
The Raven SL’s floating design lets the braking surface expand as it heats up, reducing the likelihood of warping. Rather than riveting them to the carrier, they’re bolted on. AB says the benefit is twofold: More surface contact area between the rotor and carrier for better heat dissipation (and, presumably, helps keep it stiff), and it allows you to easily replace the rotor.
The design was created using 3D CAD software with integrated Finite Element Analysis and required more than 200 hours of work to balance the low weight with the strength required to bring kamikaze riders under control.
The spider is solid billet CNC’d 7075 T651 aluminum, anodized black. The rotor is martensitic 420 stainless steel that’s ground, heat treated and laser cut to save weight but retain a fairly large braking surface area compared to other ultralight rotors we’ve seen. The bolts are custom M4 6/4 titanium.
They’re recommended for XC and Trail riding and have a rider weight limit of 198lbs (aggressive use) to 231lbs (casual use…because, you know, these are perfect for weekend warriors!). MSRP is €161 for the complete rotor and replacement friction rings are just €40. They’re based in the UK but will ship anywhere. We’ll update with US$ pricing as soon as we hear back from them. They also offer the Raven, which uses the same materials and spider but with a less-chiseled braking surface to come in at 105g.
At present, the rotors are only available in 160mm sizes, with 180mm and 140mm on the way.
The lock ring is equally gorgeous and comes in at just 5.7g (claimed). It’s available separately for €18.50 and can be used with any CenterLock rotor (but not CenterLock adapters).
That’s all well and good, you say, but I don’t use CenterLock rotors. Sit tight. Their website shows some black ceramic coated titanium ISO 6-bolt rotors coming soon that weigh in at just -wait for it- 49g for a 160mm and 40g for a 140mm. If you’re counting, that’s lighter than Ashima’s new Ai2 rotors and Scrub’s RaceDay.
