The Cyr wheel (also known as the roue Cyr, mono wheel, or simple wheel) is an acrobatic apparatus that consists of a single large ring made of aluminum or steel with a diameter approximately 10 to 15 cm (4 to 6 in) taller than the performer. The performer stands inside the Cyr wheel and grasps its rim, causing it to roll and spin gyroscopically while performing acrobatic moves in and around the rotating wheel.

The Cyr wheel takes its name from Daniel Cyr, who revived its popularity, utilising it as a circus apparatus at the end of the 20th century.

Cyr wheel requires a solid, non-slippery surface such as a dance floor, concrete or stage and a relatively large performance area. Modern Cyr wheels are typically made of stainless steel tubing or aluminium tubing approximately 1.5 inches (38 mm) in diameter. They are often composed of 3 or 5 individual pieces fixed together by steel or aluminium couplings. They may be painted and covered with an anti-slip plastic coating to add friction and protect the metal.

Smaller wheels spin faster, work better for smaller spaces, and make "no hand" tricks easier than larger wheels. Larger wheels are more graceful and there is more room for suspensions.

Since its recent popularization as a circus skill, hundreds of circus artists from around the world have performed in the wheel and it is now taught in several major circus schools.

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