Rotor ALDHU Carbon Arm Set

Rotor's new ALDHU Carbon Arm Set is a very light, stiff option with a sleek look. The cranks form part of a modular chainset that will fit a very wide range of road or gravel bikes. The performance is excellent, which is just as well because they are quite expensive.

Rotor is perhaps best known for its oval chainrings, and more recently has been producing a range of aluminium components, including ALDHU cranks, which remain available. The ALDHU Carbon is the first full carbon road option it has produced, with the KAPIC Carbon mountain bike cranks released in 2019.

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The ALDHU Carbon Arms Set forms part of a modular system, meaning that parts are purchased separately and combined to suit different bikes and riding styles. The cranks, axle, chainrings and spider if required are all available separately.

Endless options are possible – 1x or 2x, with all common chainring sizes available, plus a power meter option, the INspider, which I tested recently.

The modular system means the axle is separate and not attached to either crank, with both drive side and non-drive side having self-extracting bolts. Any play within the bottom bracket is then removed by using the preload ring on the non-drive side crank.

The cranks are available in 165mm, 170mm, 172.5mm and 175mm lengths, which cover the majority of preferences, although some rivals such as SRAM Red AXS and Shimano Dura-Ace 9100 do have more options. The aluminium ALDHU cranks are also available in a wider choice of lengths, starting at 150mm.

The carbon arms are a sleek, slim design with a gloss finish. For testing they were fitted to a setup that included a 30mm axle, INspider power meter and 50/34 compact chainrings. Setting them up is simple, and the tolerances give a very precise fit.

The performance and stiffness are impressive, with no flex that I could detect at all, including no chainring rub or deflection even under sprint efforts.

Weight and price

For the configuration on test, the total weight is 706g. The cranks themselves weigh a low 252g, although when comparing against other options the axle, spider and chainrings may need to be included.

With a 30mm axle (98g) fitted, the ALDHU Carbon Arms setup weighs 350g, compared to 334g for the Easton EC90 SL. The Easton set retails for £399, so very similar to the £394 for the Rotor when you include the £45 axle. Owning a set of the Easton cranks and able to directly compare, they are both excellent, but the Rotors just edge it, fitting together beautifully with close tolerances, and having a wider range of chainring and optional extras, making them a little more versatile overall.

> Read more road.cc reviews of chainsets, cranks & chainrings here

When built into a full chainset, Rotor claims a weight of 528g with 50/34 chainrings, which stacks up well against 609g for Shimano Dura-Ace 9100, or SRAM Red AXS with 48/35 chainrings at 587g.

For the weight obsessed who also have deep pockets, there are a few even lighter options such as the THM Clavicula SE at 293g compact or 302g standard, costing €1,195. For 1x drivetrain offerings, there is the 3T Torino at a claimed 300g for arms, axle and spider, priced at £949.

Conclusion

Overall, the performance is impressive and the cranks look great. If you want a really light setup and are happy to pay for it, the ALDHU Carbon Arms are an excellent choice.

Verdict

Impressive stiffness and low weight, with modular fit to suit all frame types