Brake rotors
Center Lock brake rotors for road, gravel and MTB, from 140 to 220 mm. Choose the diameter for the caliper and the terrain, and the construction for the heat you need them to shed.
Center Lock: the hub, the lockring, the torque
Every rotor in the selection fits Center Lock: splines on the hub and a single lockring, instead of six bolts. Check your hub first. The lockring comes with the III-PRO A1, not with the Hope rotors: order it separately, in the internal or external version depending on the hub and the tool. It is tightened with a torque wrench, to the marked torque: 40 N·m on the III-PRO rotors.
Diameter makes the torque
The rotor is a lever arm: for the same effort at the lever, braking torque rises with the radius at which the pads bite. Going from 140 to 160 mm gives at least 14% more, from 160 to 180 mm at least 12.5% more, and the larger rotor, being heavier, absorbs more heat before it gets hot. On the Hope RX Center Lock, the 160 mm weighs only 23.5 g more than the 140. In practice: 140 or 160 mm on the road, 160 on gravel, 180 and up on MTB, always within the limits of the frame, the fork or the caliper.
Floating or one-piece
A floating rotor separates the track, in riveted 410 stainless steel, from an aluminium carrier. As it heats up, the track expands without pulling the carrier with it, and the carrier sheds the heat: that is the construction of the Hope Floating Center Lock for MTB, from 140 to 220 mm, and of the RX for the road, whose rounded edge makes refitting the wheel easier. The III-PRO A2 also pairs a SUS410 stainless track with an aluminium carrier, 117 g in 160 mm. The A1, a single piece of stainless steel, relies on its large cut-outs to cool down.
Measuring wear
On the Hope rotors and the A1, the track is 1.8 mm thick when new and is replaced below 1.5 mm. Measure with a calliper on the track, where the pads rub, not at the rivets of the Hope rotors, which stand 1 mm proud. On the A1, the minimum thickness is engraved on the track.
Frequently asked questions
Center Lock or 6-bolt brake rotor?
The one your hub takes: a Center Lock hub takes a Center Lock rotor held by a lockring, a 6-bolt hub a rotor with six bolts. An adapter lets you fit a 6-bolt rotor on a Center Lock hub, not the other way round.
Internal or external Center Lock lockring?
Both secure the same rotor; only the tool changes: the internally splined lockring is tightened with a cassette tool, the externally splined one with a bottom bracket tool. On a thru-axle hub, the end cap often stops the cassette tool from fitting: then take the external lockring.
Which brake rotor size should I choose?
140 or 160 mm on the road, 160 mm for gravel, 180 mm and up for MTB and e-bikes, within the limit set by the frame, the fork or the caliper adapter. For the same effort, a larger rotor brakes harder.