Zipp

Super 9 Tubular Disc Wheel

Looking at the Zipp Super 9 Disc wheel, we remember that first-ever ride on a disc wheel. Felt weird, sounded weird, but, man, how we could fly. That was back in the day when an Araya rim that couldn't have been more than 24mm deep supported by 24 spokes was considered aero; the difference was huge.

The Super 9 is probably not night-and-day faster than that first disc we rode in the 80s, but it is still a big step up. Its changes don't seem so great when you look at Zipp's Sub 9 Disc, which is probably its closest competitor on the market.

The Sub 9 is equally aero. Both wheels, when paired up with an 808 front wheel, save you an estimated 104 seconds or 34 watts over the course of a 40k time trial. The wheels are also just about equally light; the Super 9 has a claimed weight of 995g vs. 998g of the Sub 9. In both wheels, the final 2.5cm of the perimeter have the same toroidal shape to smooth the airflow from the tire to the wheel.

But they are different wheels. As any good trainspotter will have noticed, the Sub 9, with its Zipp 808-style toroidal bulge near the tire bed, doesn't fit through the narrowest of the aero chain stays. The Sub 9 is 28mm wide at its widest. The Super 9 in comparison, starts as 27.5mm wide at the hub and narrows to 23mm wide at the tire bed. This new, flatter shape retains aerodynamics while fitting better into more bikes, though it doesn't fit in the Cervélo P4 thanks to the brake positioning.

The new shape also yields a stiffer wheel. This is more of a 40k wheel while the Sub 9 is more of a long-course triathlon wheel. The above-mentioned toroidal bulge in the Sub 9 adds some vertical shock absorption whereas the straighter shape of the Super 9 removes that shock absorption. With the stiffer wheel, power transfer is better, so less energy is lost between the crank and the tire on the road. The second element of stiffness that is increased in the Super 9 is lateral stiffness. The Super is laterally stiffer than both the Sub and the Zipp 900.

The Super 9 is most aerodynamic when you glue a 21-23mm width tire to the wheel. They went to the wind tunnel with these tires and optimized the shape of the wheel with these tires in mind. You can use narrower or wider tires, but the ride will have both greater rolling resistance and less than ideal aerodynamics.

The hub at the base of the wheel has the same innards as Zipp's 188 rear road hub. Same 17mm axle, bearing preload adjustment, same cassette. The wheel comes with a Zipp steel skewer. A track conversion kit is also available, so you can use the same wheel on the road and velodrome. Claimed weight of the Zipp Super 9 Disc is 995g.

Please Note: Zipp's Tangente Platinum Pro and cork brake pads are designed specifically for use with their carbon tubulars. Use of brake pads other than these is highly recommended against and will void the wheel warranty.