A modular crank option just got lighter

Rotor Bike Components just gave us a new chance at a lighter bike with the debut of its ALDHU Carbon cranks. Four years of development have yielded lighter and stiffer cranks compared to their aluminum predecessors, and increased options for modular crankset customization, while providing an upgrade to Rotor’s loyal fans who demanded carbon fiber cranks. Given that the introduction of disc brakes into road cycling has nudged up overall bike weight, the main goal for the new cranks was to scale down some of that weight increase without
sacrificing crank stiffness.

How much lighter and stiffer are they?

Rotor’s first-generation aluminum ALDHU 172.5 mm crank arms with 50/34 direct mount chainrings weigh in excess of 600 g, which is lean enough for extruded, CNC’d cranks. By exploiting the advantages of carbon fiber, the new carbon crank arms shed 100 grams to lower the total weight to 523.5 g for the same crankset combination. At the same time, the cranks’ absolute vertical and horizontal stiffness were increased by 11 percent and 36.1 percent respectively.

Rotor claims 260 grams but on our scale, we got 258 grams.

Featured crankset combinations

Since no two cyclists are exactly alike, when comfort and/or performance determine the quality of a ride or the outcome of a race, the ability to precisely dial in personal preferences becomes crucial. The ALDHU Carbon cranks can be combined with different types of spiders, chainrings, and axles to optimize comfort and performance. To guide the selection process, Rotor has organized possible crankset combinations into four categories: Standard, Superlight, Aero, and Full Aero with 1x and 2x configurations in all except Standard.

Twin Leg Technology

ALDHU Carbon crank arms have been designed in combination with Rotor’s 30 mm axles. The patented interface between crank arms and axle offers a simple assembly but with a firm fit. This design solves a specific problem, which is that power losses are mainly generated by axle torsion under pedaling force. To address this, the robust axle reduces power losses that occur when force is exerted on the left pedal. The balance achieved to minimize these losses is called Twin Leg Technology.

OCP Mount

This technology allows the rider to adjust the orientation of Rotor’s Q RINGS oval chainrings by degrees relative to the crank. OCP Mount is based on the combination of three independent elements: axle, right crank arm and spider with oval chainring (or in the absence of a spider, a direct mount Q RINGS). The patented crank interface for a DM Q RINGS allows for the most precise adjustment of an oval chainring to date.

With these new benefits built into the crank structure, users who place a premium on choice can customize their cranksets owing to ALDHU’s modular structure. Rotor first introduced this concept into its product range in 2017. Since then Rotor has added components to the ALDHU category to further extend its customization configurations.

Available upgrades

ALDHU’s modularity offers cyclists the added advantage to upgrade to the new carbon crank arms if they already use an ALDHU or VEGAST crankset. A 10 mm Allen key, a pair of ALDHU Carbon cranks, and two minutes are all it takes to complete this easy upgrade.

Users can easily add power measurement with the INspider power meter like our test crank, which measures power, cadence, and balance, and employs two proprietary metrics, Torque 360 and Optimum Chainring Angle.



ALDHU Carbon crank arms are available in 165, 170, 172.5 and 175mm

Arms only $449 (Axle, spider, spacers or chainrings not included)

Full crankset with 2x (round) rings start at $724, if you add INspider (power meter) it is $1249.

For more info head to

For the ultimate aero advantage, the Aero Crown replaces the front chainring bolts and only adds 45 grams.

Our Build Breakdown

When adding up our build we ended up with two weights. The above aero build hit the scales with a total weight of 705 grams. Without the Aero Crown and using the regular chainring bolts we have a total weight of 660 grams.


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