The lightweight Rotor Aldhu alloy crankset launched at Eurobike last fall, and now they’re getting a power meter option and new 30mm diameter track spindle. They’ve also added four shorter arm sizes, helping the modular system to fit more riders and bike sizes.

2018 Rotor Aldhu are their lightest road bike cranks

2018 Rotor Aldhu are their lightest road bike cranks

They’re named after Carlos Sastre’s Alpe D’Duez win in the 2008 Tour de France, which helped him secure the overall that year on their Q-Rings. It’s a completely modular system, letting you choose the chainring combo, arm length and spindle type you need.

2018 Rotor Aldhu are their lightest road bike cranks

At launch, they only offered down to a 170mm. Now, you can get 150/155/160/165/170/172.5/175 arm lengths in their 3D+ arms, which are drilled lengthwise and are both stiff and light.

The chainrings are machined from a single piece of aluminum and come in oval and round. Three spindles are available – Rim brake road (43.5mm off set), disc brake road with 2.5mm more (46mm) chainring offset, and a new 30mm diameter track crankset. The latter pairs with 49, 50 or 51 tooth chainrings, which bolt a direct-mount spider rather than full direct mount chainrings. The doubles, as a system, bring the count from 22 parts down to 14 parts, so the modular system lets shops stock fewer parts while still having what you need.

2018 Rotor Aldhu are their lightest road bike cranks with a powermeter

The spindle lets you tweak the clocking rotation of the oval, so you can customize its position to suit your pedaling.

The standard version comes in at a claimed 599g for spindle, arms and double chainrings. They’re machined of 7075 alloy and come with a lifetime anti-corrosion warranty. Retail is $600, out now. Chainring combos are 52/36, 50/34, and 53/39. Direct mount 1x options coming, likely in a 38-52 tooth count range for cyclocross and gravel. They also offer a regular asymmetric Shimano compatible 4-bolt spider if you prefer to run Shimano rings on your Rotor cranks, which would be a good way to add this:

first look at new Rotor Aldhu 2inPower dual sided power meter cranksets with oval or round chainrings

Not officially announced yet, they have ported their 2inPower dual-sided power meter system from the mountain bike and standard road cranks to the Aldhu system. Weights and pricing are TBA, but we can expect it to look a lot like the MTB power meter cranks:

The driveside strain gauge is hidden inside the arm, and the non-drive uses a spindle-based, four-gauge system to measure torque and deflection all the way around your pedal stroke. You can read more about the tech in this post.

2018 Rotor Aldhu crankset chainring actual weights

Actual weight for the Aldhu Q-rings ovals is 186g for 52/39, and 170g for the round equivalent. Their UNO cassette, which they claim is the lightest mass production cassette in the world, is just 134g for a full 11-speed cassette.

rotor uno cassette actual weights

The secret is their completely machined hollow steel main frame, which uses just a single cog’s worth of contact point on the freehub body. The alloy carrier with the top two cogs rests on it but has no “teeth” to engage with the FH body.

Rotor UNO is the lightest road bike cassette

They say the teeth are chamfered not just for optimum shifting performance, but also to be very quiet. The full UNO hydraulic shifting group is available, but you can buy this part separately if you’re just needing to replace or upgrade a cassette.

Not official yet, but a little birdie may have whispered to us that this 11-28 version will eventually share the same steel 11-21, paired with an alloy 23+25 for a closely spaced 11-25 offering. They may also have a larger steel lower cluster in the works that will include an 11-32 option, with possible 11-30 and/or 11-36 variants.


  1. Smale Rider on

    Looking at the 4 bolt pattern, and the 4 bolt pattern on the Praxis Zayante carbon (with limited info) I wonder if the spider can be pulled off the new looking praxis rings and put onto this Rotor spider. I also hope they actually bring over their 46/30 direct mount, an actual compelling reason to use rotor cranks. And lastly I hope they make their “new” powermeter across the full crank arm length range, I totally was let down by the lack of 2inpower. Right now lightness isnt a compelling reason for me to move past my current 3d+.

    • TheKaiser on

      Where are you seeing a “4 bolt pattern”? There are 4 arms, but from the pics and my understanding of what is written above, it looks like these rings are a single unit machined from a single piece of aluminum, as with the Cannondale Spiderring.

      • Smale Rider on

        “They also offer a regular asymmetric Shimano compatible 4-bolt spider if you prefer to run Shimano rings on your Rotor cranks”

        New praxis crankset looks like it runs 4 bolt shimano style rings, which makes me wonder if a new 4 bolt ring from praxis can be put onto a rotor crank. More specifically id be interested to get that 48/32 from praxis on this rotor crank.

        • Bill B on

          The Praxis looks like its 4 arms are equidistant from each other. Shimano, Rotor are not. FSA crank look like they have equidistant arms. You can get the Omega’s with 48×32 or 46×30.

  2. satanas on

    The Praxis 4 arm rings were said here to be something like 160×104 bcd, IIRC, so not much use to anyone else. If they’d been straight 104 bcd I would have been interested.

    Agreed they should offer their 46×30 rings to fit, which are already one piece anyway.

  3. BMX on

    That cassette would make an absolute mess of anything but a hardened tool steel cassette body, an alloy one or ti one would be munched to death by the small amount of contact points. Also is probably very noisy like the original SRAM red dome cassette.


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