Zipp’s new Super-9 will be one of the world’s first carbon clincher discs when it is released in January, dropping significant weight relative to most aluminum/carbon hybrid clincher discs while also allowing for the use of ultra-low-rolling-resistance clincher tires.
Zipp says it is the company’s fastest disc ever due to the use of said tires and extensive research and development into the transition between tire and rim.
The new disc has seen nearly two years of development, including race testing under Tony Martin. Martin rode the wheel to a silver medal in the Olympic time trial, a second world TT title, and a crop of other international podiums — as well as a few flat-tire disappointments at the Tour de France.
The Super-9 uses the same brake track technology as the rest of Zipp’s successful range of carbon clinchers, employing high-temperature resins to prevent the tire blowoffs associated with the industry’s early carbon clincher efforts. That carbon brake track, which we are warmly familiar with following our recent testing of Zipp’s 202 Firecrest Carbon Clincher, offers industry-best dry braking performance with excellent outright power and modulation. It is as close as we’ve found to the performance of an aluminum brake surface when dry.
By going with a carbon clincher, Zipp could carefully shape the brake track to provide a smoother transition from tire to rim — an area that seems to be the next frontier in gaining aerodynamic advantages. Wheel giant Mavic has focused on this area as well, introducing its CXR80 wheelset with small rubber strips intended to completely flatten the tire/rim transition.
While Zipp hasn’t taken tire integration that far, it has spent quite a bit of time perfecting its own brake track. On the Super-9 CC, the two sides of the brake track are not parallel; rather the tips point inwards slightly, and the disc bulges out to its widest point just below the brake track. Following the trend of Zipp’s other carbon clincher offerings, the tire bed is very wide: The center of the brake track is 26.42mm wide and the widest point on the disc is 27.5mm.
Zipp says the disc is still optimized for a narrow tire, 21 or 23mm wide, but because of the shielding effect of the frame running a wider tire won¹t do as much damage to the aerodynamics as it would on the front wheel.
“Since most modern tri’ or TT bikes have a seat post that blocks the leading edge of the disc, it is a bit more ‘tire agnostic,’ let’s call it. You can run a 25mm tire, for added comfort or tire protection, with far less of a penalty since you are only affecting the [air's] exit speed, and not the overall laminar flow characteristics across the entire disc surface,” explained Zipp’s David Ripley.
The disc that arrived last week at VeloNews.com World Headquarters last week weighs only 1088 grams, significantly lighter than the claimed weight of 1175g. The disc is adaptable for track use, and features a max weight limit of 275 pounds plus a max tire pressure of 125psi. The 188 disc hub is compatible with both 10- and 11-speed drivetrains.
The budget-conscious need not apply: price for a rear disc is $2,375.
Read more: Velonews.com