Zipp 303 S Carbon Disc Rear Road WheelTaking its design from the higher-spec Firecrest 303 model, this rear wheel is ideal for modern “go anywhere” road bikes. Zipp has also updated this model with a wider rim to improve rider comfort, handling and aerodynamics. Expanding greatly on its heritage of conquering the Spring Classics, this 303 wheel maintains its ideal-for-every-terrain 45mm rim depth. However, this model adds a significantly wider internal width to provide greater performance and ride quality in almost every measurable way. Road bikes are more versatile than ever no matter the road surface, but just as fast as before. The 303 S offers an entirely new rim profile and design to optimise rider performance on this new breed of bike. This wheelset is tubeless compatible and designed for disc-brake bikes, allowing the ability to run wide tires at lower pressures for race-ready speed on or off the tarmac.45mm Deep Rear WheelThe 303 S is among Zipp’s lightest wheels, optimised for top aero performance with a 28mm tyre but capable of handling gravel tyres up to 50mm wide. The key innovation is in the 303 S’s rim design. Its 45mm rim depth is the same as its predecessor, the 302 Disc brake. But its external rim width is 2mm wider, at 27mm, and its tyre bed is a full 7mm wider, at 23mm internal width. That rim platform is designed to be the fastest with a 28mm tyre. The wide rim optimises tyre profile to allow lower tyre pressure. That helps to reduce rolling resistance and provides a more compliant ride. The result of all this is a 10 watt savings vs. a top peer wheel in total power required to ride 40kph on a flat road with a 28mm tyre, according to internal Zipp testing.This ground-breaking wheel also features all-new cosmetics, setting the rider apart from the pack, and comes at a very attractive price.Please Note: Shimano/SRAM freehub option is for 11 speed Shimano/SRAM XD cassettes. The SRAM XDR freehub option is for 12 speed SRAM XD road cassettes.Features: Rim Material: Carbon Fibre with updated Zipp graphics Brake Compatibility: Disc (centre lock) Rim Inside Width: 23mm Rim Profile: Symmetrical Rim Type: Clincher Rim Finish: UB Fibre / Bake-on Labels / Matte Clear Coat Spoke Type: CX-Sprint Spoke Count: 24 Spoke Pattern: 2-cross Nipple Material: Brass Axle Type: TA 12x142mm Bearing Type: Cartridge – Stainless Steel Driver Mechanism: 3 pawls leaf spring Tubeless Ready: Yes Hub: 176 DB hub with centre locking interface Single or Pair: Single Brake Compatibility: Disc brake Weight: 819gBuy Zipp Wheels & Tyres from Chain Reaction Cycles, the World’s Largest Online Bike Store.