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Asymmetric Chainring

Founder, Mr. Mamil
Osymetric Chainrings
An Osymetric Chainring with Rotor Crankarms

An asymmetric chainring is a chainring with an uneven shape and size, meaning it is not round or symmetrical.

Asymmetric chainrings are also known as non-round, oval chainrings or, elliptical chainrings. The term comes from the engineering and design of bike drivetrains, which often use asymmetric chainrings to optimize pedaling efficiency and power.

Asymmetric chainrings are designed to match the natural variation of a cyclist’s force and speed to the pedals during a revolution. Asymmetric chainrings can reduce the dead spots, increase the torque, and smooth the pedaling cadence. Asymmetric chainrings can help cyclists improve their performance, comfort, and biomechanics.

Some examples of asymmetric chainrings are:

  • Osymetric, which are cam-shaped chainrings that have two large and two small radii, are used by some professional cyclists such as Chris Froome for this Tour de France wins.
  • Rotor Q-Rings, which are elliptical chainrings that have five adjustable positions.
  • AbsoluteBlack, which are oval chainrings that have a narrow-wide tooth profile and are used by some mountain bikers and gravel riders.
Alex Lee at Mr.Mamil

Alex Lee is the founder and editor-at-large of Mr. Mamil. Coming from a professional engineering background, he breaks down technical cycling nuances into an easy-to-understand and digestible format here.

He has been riding road bikes actively for the past 12 years and started racing competitively in the senior category during the summer recently.