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Universally compatible & insanely light, ROTOR eKAPIC is an e-MTB race crank with a twist

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There is no shortage of e-bike news as of late, and one thing is clear — bikes are getting lighter, faster, and more capable. It seems that every major brand has a full-blown race bike ready to tackle the GNCC or the local trails.

Spanish component manufacturer ROTOR is jumping in the e-mtb category with both feet releasing an e-mountain bike version of its lightweight workhorse crankset — the eKAPIC.

ROTOR eKAPIC crankset full with bumpers

Narrow Q-Factor for comfort

If we’re being honest, saving a few grams at the cranks won’t really put a dent in a 45+ pound e-bike. So the weight’s not the whole point here.

The eKAPIC crankset keeps riders in a familiar position while pedaling, boasting a Q-factor closer to that of a conventional (let’s call it acoustic) bicycle. The idea is that the narrow Q-factor allows riders a seamless transition from bike to bike. The result is less hip/knee pain that comes from an awkward and sometimes unfamiliar pedaling position.

ROTOR eKAPIC crankset Q-Factor

The Q-factor depends on the motor and the compatibility of your bike, but the eKAPIC looks to come in about 5mm narrower than most e-mtb cranksets. The eKAPIC employs the same ISIS spline across the line, with the most narrow offering at 169mm (Fazua) and widest at 184mm (MAG BROSE).

Trinity Drilling System

ROTOR is well known for crafting some of the lightest alloy parts around, and the eKAPIC no different. E-bikes take more abuse than conventional bikes, mainly because of the weight and aggressive riding. Aluminum is an excellent option for components for strength, durability and to lighten the load.

rotor ekapic lightweight alloy crankset for e-mountain bikes

The eKAPIC starts as a piece of 6082 aluminum, then forged, CNC’d, and drilled with ROTOR’s Trinity Drilling System (TDS). ROTOR uses the TDS on most of its higher-end alloy cranks to remove material inside the arms, resulting in a lighter crankset without compromising stiffness-to-weight.

The eKAPIC weights in at a claimed 403g for a 170mm crankset…a weight that rivals many carbon fiber arms, but able to remain narrower for a better Q-factor

ROTOR universally compatible chainrings

The eKAPIC uses ROTOR’s proprietory direct mount chainring, but the eKAPIC receives a beefed-up tooth profiling and fit. The new chainrings come in 32T, 34T, and 36T sizes and are compatible with SRAM, Shimano, and KMC mountain bike chains. ROTOR boasts that its chainrings are currently the only rings 100% compatible with all 1x e-mtb groupsets on the market — compatible with Bosch, Brose, Fazua, and Polini motors.

ROTOR eKAPIC crankset universal tooth chainring

This compatibility comes from the universal tooth pattern, crafted in collaboration with the four primary motor manufactures. ROTOR has made eKAPIC cranks compatible with Bosch Gen 4, Brose MAG, Fazua Evation, and Polini E-P3 144mm motors.

If you shred hard and are looking to protect your crankset investment or get matchy-matchy with your e-mtb, the eKAPIC fits all the bumpers and protective coverings as the traditional KAPIC.


ROTOR eKAPIC crankset sizing and specs

ROTOR eKAPIC pricing

  • Crankarms $150.00 —  same price for Bosch, Brose, Fazua & Polini.
  • Direct mount chainrings $80.00 each

The ROTOR eKAPIC is available immediately for purchase online or at your local bike shop.


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Joe Maki
Joe Maki
2 years ago

5mm narrower!, 2.5mm per side (about 1/10″) . I wouldn’t boast about that 🙂

Bike Industry Insider
Bike Industry Insider
2 years ago
Reply to  Joe Maki

In the bicycle design world millimeters are gross increments, but I get your point

2 years ago

Aliexpress has some cranks that look exactly like this. they even have the same drilling blah blah that these talk about.

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