Profile Design 38TwentyFour Carbon Clincher Wheelset. Get Free Wheels! While supplies last: buy a set of Profile Design 38TwentyFour Wheels PD 38T and get a set of Profile Design 30TwentyFour Alloy Wheels PD 30TA a 379.99 value Free. An impressive amount of research and technological know how from Profile Design has resulted in their absolutely superb 38TwentyFour Carbon Clincher Road Wheelset. The 38 in the name represents the 38mm deep carbon fiber rim depth which ensures confidence while riding in crosswinds as well as great acceleration and hill climbing capacity. A team of technicians utilized Computational Fluid Dynamics to manipulate width, depth, and conicity while the utilization of historical wind speeds, angles, and race day conditions on popular road and triathlon courses around the world resulted in a rim depthprofile optimized for real world aerodynamic performance. It's not enough to simply fly along roads in training and competition, so Profile Design ensures that braking performance, too, was optimized courtesy of proprietary resins in the rim's braking surface as well as the creation of their own carbon fiber specific brake pads to reduce braking distance. And the TwentyFour in the wheelset's name refers to the rim's 24.5mm width, which equates to a more comfortable ride and cornering with unparalleled confidence. Wider rims have some counter intuitive effects when compared to those standard 19mm rims: they actually decrease rolling resistance and increase aerodynamics. The 38TwentyFour wheelset's hubs are a technological marvel as well as they're forged from 6061 T6 aluminum then precision machined with a tolerance of 100th of a millimeter increasing durability, strength, and stiffness. The freehub body is machined from 7001 T6 aluminum then shot peened hard anodized to create an 18% increase in material strength compared to standard aluminum freehubs. This prevents the cassette from digging into the freehub body resulting in better shift performance and increased power transfer. These hand built wheels also feature Sapim CX Ray bladed, stainless steel spokes 20 front and 24 rear to enhance the stiffness and aerodynamics.