Your bike might be rocking one of the best disc brake systems on the market, but there are still ways you can boost your stopping power. Rotors are one way. SRAM’s latest mountain bike brake rotor is this all-new HS2. At 2mm wide, it’s thicker than the 1.85mm CentreLine discs it replaces, with a weight increase of around 35g for the 180mm size I tested. The braking surface features slanted slots that leave more metal for pads to grab, and the pattern incidentally looks a bit like a flipped version of the old Avid G2 cleansweep rotors that were popular with sponsored SRAM downhill racers.

The redesign targets heat management as well as extra bite, with SRAM claiming 7% extra power and up to 40% better thermal management; in part due to a special black heat-dissipating coating on several of the disc’s spokes. Another benefit is that the stiffer rotors are harder to damage or warp.

SRAM HS2 brake rotor

I’ve used the rotors on several bikes, in different diameters and paired with various calipers and the improvement compared to Centreline is very noticeable. Bite is much increased, so there’s a perception of more power even if there’s only a marginal increase in actual power. It’s also very usable as it’s not too grabby, and the system felt both snappier and more consistent too.

Despite downsizing from 200mm Centreline rotors to 180mm HS2 versions, I’m convinced that the brakes gained more bite and also a more solid and predictable feel, which is more improvement than SRAMs claim of 7%. Above all, the levers ‘thunk’ to a reassuring stop when they bottom out on the disc; it’s similar to the sensation of a perfectly bled front brake to a slightly spongy rear, with a rock-solid lever feel when grabbing hard in panic stop situations. It’s quiet even when wet and any concerns of thicker rotors causing brake rub were unfounded too; this is simply not an issue.