Engineering team

We knew that nobody applies constant, even force throughout a pedal stroke and we theorized that it would be possible to revolutionize the world of cycling if we could successfully eliminate the dead spots in a pedal rotation. We saw opportunity in a challenge where others had previously failed.

Pablo Carrasco – ROTOR co-founder, on the origins of ROTOR

Hand Made

UNO Break away

ROTOR started by seizing on this theory. Ignacio Estellés and Pablo Carrasco, an aeronautical engineer, speculated that if cranks fixed at 180º and pushing round chainrings is biomechanically inefficient, how much more efficient would pedaling be if it wasn’t limited to an assumed constant force throughout a 360º rotation?

By positing this theory, the objective was to achieve a more natural pedal stroke inline with the legs’ strengths and weakness, which would eliminate the dead spots and take greater advantage of force applied to the pedals. The tenacity with which Estellés and Carrasco persevered marked the difference between present-day ROTOR and previous attempts to prove this theory.


Improving pedaling efficiency by varying drivetrain resistance during pedaling guided every ROTOR innovation, starting in 2000 with the ROTOR Box. The crank system solved the challenge with an awkward mechanism that required specific frames for its installation, and this earned an almost immediate rejection from the Union Cycliste Internationale (UCI), which required a special adapter to accommodate a wider range of frame models.

The next four iterations: RCK, RS03, RS4, and RS4X Hexadrive evolved ROTOR’s main objective to improve pedaling efficiency but it wasn’t until 2006 and the debut of Q-Rings when ROTOR’s flagship product gained a firm foothold in the cycling world.

Q- Rings solved the challenge by revising traditional circular chainrings to create a variable drive radius, which would take advantage of the areas where the most force is applied during the pedal stroke, thus giving greater forward momentum, and reducing the “dead spots.” Where others had failed, oval Q-Rings successfully minimized the negative effects of dead spots during a rider’s pedal stroke while maximizing power output.

A Grand Tour Win

Despite Q-Rings’ intelligent design, ROTOR was continually plagued by comparisons to failed attempts at elliptical chainrings by other brands and ROTOR struggled against these comparisons (and still does to this day). That was until July 27, 2008, when Spanish pro racer, Carlos Sastre, won the Tour de France with Q- Rings and ROTOR’s future changed overnight. Sastre’s win instantly thrust ROTOR into the spotlight and opened the door to new cross-discipline product innovations. Cranks and bottom brackets with specific characteristics that coud meet the distinct demands of certain disciplines and that could be paired with Q- Rings promised unforetold performance benefits.

Triathlon, MTB, cyclocross, UBB

Sustained maximum output, better traction, and faster acceleration became ROTOR’s new goals in product development and to achieve those, ROTOR recruited state-of-the-art materials and designed new cranks and chainrings. Aeronautic-grade aluminum, Q-Rings with 16% vs. 10% ovality, and single chainrings for 1x drivetrains marked key developments in ROTOR’s evolving product line. At the same time as ROTOR was expanding its range of cranks and chainrings, bottom bracket “standards” also grew exponentially, which ROTOR confronted with its Universal Bottom Bracket system. If innovation and design are in ROTOR’s DNA, then compatibility provides motivation to embrace the challenge to craft ROTOR components for all cyclists.

Made in Europe

ROTOR’s strategic location next to Spain’s aerospace industry happened by design rather than chance. EDR C.N.C. Machining, which has manufacturered ROTOR’s products since day 1, also supplied products to various national militaries based in the area surrounding ROTOR’s headquarters outside of Madrid. As ROTOR grew its product range, it reached out to its European neighbors to form partnerships that espoused the innovation, technical know-how, and engineering prowess, which ROTOR’s products embody. In recent years, ROTOR has grown from a single product (ROTOR System), to become an international manufacturer of high-quality components developed by our own engineers, made in Europe, and patented worldwide.