First introduced in 1996 and continually improved over the past two decades the iO RIO has won more Olympic track medals than any other wheel in the world.The latest generation iO delivers an even greater competitive advantage. It features a wider rim to better integrate the slightly larger tubular tires that are popular with track racers. And each of the five spokes has a NACA profile for further improved aerodynamic drag. The new iO is ready to break its own records. Key benefits Unbeatable aero performance shaves seconds off your time. New wider elliptical rim shape. 5 aircraft wing spokes for lower wind resistance. Engineered stiffness for sharp steering and maximum power transfer. Wider rim for maximum stiffness. Monobloc construction. Woven 3K carbon fiber. Roll faster with greater efficiency. Tubular rims and interchangeable QRM cartridge bearings minimize friction. Hubs Sealed cartridge bearings QRM Axle material: aluminum Body: aluminum QRM bearing preload technology Delivered with User guide Fixing nuts Valve extender Wheelbag Rims Tire: tubular Structure Woven carbon fiber 5 aircraft wing shaped spokes Tyre: tubular ETRTO size: 28 tubular Intended use Recommended tire sizes: 18 to 25 mm For a longer longevity of the wheel Mavic recommends that the total weight supported by the wheels doesn't exceed 120kg bike included Max Pressure: see indication on wheel and tire If they differ use the lowest of the 2 Minimum and maximum allowed tyre width: see indication on wheel Versions Color: Black only Information on specified weight The weight of the wheels is announced at +/-5% in XD/XD-R and Center Lock version without quick release nor valve nor rim tape