Zipp Super-9 Carbon Disc Brake Tubeless Disc Rear Wheel Among the lightest disc wheels available at 999 grams, the Zipp Super-9 Carbon Disc Brake Tubeless Disc Rear Wheel is a super-sized addition to your modern triathlon and time trial bike. The shape has been refined and runs wide and parallel from the hub, feathering inward as it meets the hookless tyre bed. This wheel is engineered to suit wider tyres run at lower pressures throughout your TT or Triathlon. Guided by Zipp's Total System Efficiency (TSE), Zipp has remade the Super-9 from the rim-tire interface up to its ceramic bearings, resulting in a design that is efficient, fast, smooth, and stable. The Super-9 is fastest with 28mm tubeless tires inflated to lower than traditional pressure, which makes for better handling and cornering on a disc that's significantly stiffer and more durable than its predecessor.