The Rotor REX 2.1 1x10/11-speed crank closes the gap between Rotor's REX 3 and the performance-orientated REX 1 crank, because it is featuring trinity drilled, cold forged crank arms and a 30mm aluminium UBB axle. Furthermore it offers a perfect balance between low weight, rigidity and durability.
The crank arms of the Rotor Rex 2.1 are made of forged and CNC machined 7075 T6 aluminium which have been trinity drilled for a further weight reduction. Rotors axle system has been specifically developed for multiple BB systems. In addition Rotor has extended the compatibility of the Rex 2.1 because now it's equipped with an improved ultra stiff 30mm aluminium UBB axle.
The "UBB System" is not a standard. It's all standards because it allows the installation of almost any 24 or 30mm Rotor axle crank on your bike, regardless of its BB type.
Note: You will find a compatibility chart under "attachments"!
This crank is manufactured using an improved version of RotorŽs proprietary "Trinity Drilling System" technology during manufacture. Due to the larger axle-crank contact area of a BB30 crank, all three holes can be drilled from the axle side of the crank arm, allowing further optimization of wall thicknesses. It improves both the weight and the weight-rigidity ratio of the crank arm.
The REX 2.1 XC1 MTB cranks can be used with Rotor QX-Rings (not included in delivery), noQ rings and also be used with any standard chainrings for 76mm bolt circle diameter.
The precisely adjustment of the cup preload is achievable because of an compression ring with nut.
Q-Factor: 163mm, Chain line: 56mm
Symbolic picture: The picture shows the crank inclusive chainring, while the delivery includes only the crank.
Fitting for derailleur: 11-speed
Included in delivery: without bottom bracket cups and chainrings
crank, aluminium chainring bolts, spacer
Material: 7075 T6 aluminium
Weight supplement: at 170mm crank arm length, without BB and chainrings)