Zipp s 303 Firecrest Tubeless Disc-brake wheel is designed for the real world a world of imperfect conditions, road surfaces, and elements where the bottom line is simple. Efficiency = speed. It s faster, lighter, and more capable over varied terrain, whether the surface is pavement in all its conditions or no pavement at all. New Zipp graphics and cosmetic identity that scream speedVersatile endurance wheel for the modern road bike with tubeless and hookless rim profileLighter Weight than its predecessor, making it nimble and fast.Tubeless Made Easy, optimised tyre bed sign allows for simple tool-free installation and removal with no need for an air compressor to seat the tyre.Ultra-wide 25mm rim profile creates a better tyre interface to be fast on or off the roadNew 40mm rim depth makes a light and aero wheel in every situationNew ZR1 DB hub is engineered in Germany with better seal design for improved durability and quicker response with 66 points of engagementShips with 12mm front and rear end capsCentre locking rotor interface. Lock ring is included with the wheelsXDR or SRAM/Shimano driver bodiesCampagnolo driver body sold separatelyDeeply rooted in Zipp s drive to conquer the Spring Classics, the new 303 Firecrest is remade with a purpose-made approach for the demands of modern road bikes. When it comes to going fast on a bicycle, efficiency means reduced: Wind resistance, rolling resistance, rider fatigue, weight. The 303 Firecrest Tubeless Disc-brake was designed using real-world direct measurements (vs. primarily wind tunnel or computer simulation). The results were huge. Its rim is slightly more bulbous in design than its predecessor, with a 30mm outside width, a 25mm internal width, and a 40mm rim depth. The profile provides low drag and an improved transition between rim and tyre, boosting aero efficiency on the road. The wide rim stance also features less tyre deflection for reduced rolling resistance. The combination of the wider tyre, increased tyre volume, and lower tyre pressure helps to reduce rider fatigue by smoothing out the ride over imperfect pavement and road conditions the tyre and wheel system absorbs the shaking, not the rider. At the centre of the 303 Firecrest Tubeless Disc brake is a versatile and durable new hub, the German-engineered ZR1 DB. This hub features 66 points of engagement for quicker response. The 303 Firecrest Tubeless Disc-brake wheel is for dedicated cyclists who aspire to the latest in technology. Its competitors in races, against peers, or simply conquering personal limits. This is about becoming faster and matching your motivation to the most advanced technology.Orientation (wheels): RearSize (wheels): 700cRim construction: CarbonTire compatibility: Clincher Tubeless ReadyRim depth: 40mmSurface texture: ABLC SawToothBrake compatibility: Disc (Center Lock)Rim - inside width: 25mmRim profile: SymmetricalRim finish: UD fiber, adhesive decalsColor (Decal): StandardNipple material: AluminumNipple anti-rotation: Sapim Secure-LocSpoke type: CX-SprintSpoke count: 24Spoke pattern: 2 CrossHub: ZR1 Disc BrakeDriver body type: SRAM/Shimano Road or SRAM XDRColor (hub): BlackAxle type (Wheels): TA 12x142Axle material: Aluminum front & rearBearings: Cartridge - Stainless SteelDriver Mechanism: 6 Pawls Leaf SpringDriver body material: AluminumMax tire pressure: 73psiMax recommended rider weight: 250lbsPart Weight (g): 739Please Note: The below tyre brands have communicated to us that their tubeless models are compatible with our tubeless hookless straight side wheels. Riders wishing to use regular clincher tyres should check with the manufacturer if they are compatible with hookless rims. This is a guide and we still recommend consumers confirm compliance with their chosen tyre manufacturer: Zipp - Tangente Speed RT25, R28, and the Tangente Course G40 gravel tyreSchwalbe Rene Herse