Sure, the clinchers are nice and convenient, but we've always thought that the Zipp 303 Firecrest Carbon Tubular Wheelset was the better choice when pure speed was the issue. The elemental difference between the two versions is the significant weight difference. These tubular wheels are around 220 grams lighter, and you'll benefit from their feathery lightness on either flat ground or relentlessly hilly rides.
The 45mm rim depth on the 303 wheels is better for lighter riders, or for those who feel concerned about being buffeted by crosswinds. And as it did on the 404 Firecrest rim shape, Zipp's engineers developed a new 303 Firecrest rim profile that moves the center of pressure in towards the hub, away from the outside edge of the rim. The tangible benefit is a marked decrease in the leveraging effect of stiff crosswinds on the steering axis -- you'll be able to ride more confidently and faster in blustery conditions. Also, their dimpled 45mm rims are still deep enough to offer serious aerodynamic advantages. In fact, the Firecrest is 8% faster than the last generation 303. Even with this marked increase in shear speed, the 303 Carbon Tubular Wheelset comes without an increase on the scales.
We love that Zipp is all about aero, but it made another improvement with these wheels -- one typically glossed over in discussions of carbon tubulars: Heat-dissipation. Increased heat dissipation = increased safety. Zipp's carbon tubulars are setting an unprecedented standard for heat dissipation. Years of testing led to the development of its heat-resistant resin system. As you bomb down long, high-speed descents with heavy braking sending rim temperatures soaring towards 500 degrees Fahrenheit, there's no risk of a burst sidewall with Zipp carbon tubulars. The new resin system was a must-have to ensure the stability and durability of the tubular sidewalls. However, the braking power is exactly the same as Zipp's other carbon rims, and the silica-ceramic composite used in the braking track gives even, fade-free quality in any weather conditions as long as you use Zipp's Tangente Cork pads.
Zipp uses unidirectional carbon throughout the rim, but the tubular sidewalls and outer rim wall use woven carbon for added toughness on the tubular shape. The wheels roll on Zipp's 88 front and 188 rear hubs. They both use 17mm aluminum axles for strength and supreme stiffness, and they have a preload adjustment so that you can dial them in to that bearing nirvana -- just between a bit of play and slightly too tight. Speaking of bearings, Zipp's Swiss-made bearings enjoy a reputation for exceptional smoothness.
The 303 Carbon Tubulars get 18 radial spokes in the front and 24 spokes in the rear wheel, split between both sides -- crossed on the left and radial on the right. The Sapim CX-Ray stainless steel ovalized spokes are far and away the best in the industry. They're lighter than most round butted spokes, and the coining process used to produce their aerodynamic shape makes them stronger and very durable. They are anchored to the full-carbon rims with Sapim alloy nipples.
One more design aspect of note is the width of the 303 Carbon Tubular wheels. With its prior development, Zipp has experienced many benefits by using a slightly wider rim. Firstly, the aero properties are best exploited when paired with a like-sized tire. And since most of us train and even race on 23-25mm tires, the use of a wider 28.5mm width 'fits' the tires better for optimum aerodynamics; in addition to changing the shape of the tire for a few more benefits. These are due to increasing the total air volume inside the tire. This increase in volume increases the cornering contact patch without increasing the rolling resistance. It also allows you to ride at a slightly lower air pressure as the straighter sidewalls possess more stability and deflect less against obstructions on the road and against cornering forces. The chance of pinch flats with straighter sidewalls is also lessened. All good things.
The Zipp 303 Firecrest Carbon Tubular Wheelset is perfect for hard riding in hard terrain. Uphill or into the wind, they're snappy and fast. And since they have a few extra spokes compared to the 404 wheels, they're a great choice if you have to train on your race wheels. You can get them in the color Black with either Black or White Zipp decals. They come with either Campagnolo or Shimano/SRAM compatible freehubs, and the Shimano body is equipped for the new Dura Ace 9000 11-speed shift system. A set of Zipp steel skewers are included as well as two Zipp alloy valve extenders, Zipp rim strips, and Zipp Tangente cork brake pads.
Please Note: Zipp's Tangente Platinum Pro and cork brake pads are designed specifically for use with its carbon tubulars. Use of brake pads other than these is highly recommended against and will void the wheel warranty.
Buy Zipp 303 Firecrest at Sepedakita