Hot on the heels of the recently released 60 and 30 Clincher wheels, the company’s most affordable aero wheels to date, comes the brand new Zipp 404 650c Firecrest Carbon Clincher wheels, designed with smaller athletes in mind. And they’ve also launched the new Zipp Vuka Stealth aero bar as well.
Let’s start with the wheels first. Without exception, nearly all road bikes are designed with 700c (a 622mm rim) wheels these days. This wheel size can be a problem for shorter cyclists though, as packaging the wheels into very small frames can be problematic. A solution, and the one SRAM is using with these news wheels, is to look to the old French sizing system, 650, and it’s three sizes, ‘A’, ‘B’ and ‘C’. 650b was popular with French touring cyclists, and more recently is being adopted on modern mountain bikes as an alternative to 26in and 29in wheel sizes.
But it's 650c, with its outside diameter of 571mm, is the size of Zipp’s new 404 wheels. This 650c wheel size has been a popular choice with shorter cyclists and time trial riders for some time. A small handful of frame builders still offer time trial and triathlon bikes built around the wheelsize, but it's fair to say it's never been that well supported. UK frame builder Burls for example offers a 650c Women’s Time Trial Bike. As does Planet X.
The benefits of a smaller wheel for smaller cyclists is obviously one of a better fit and reduced weight. There have also been plenty of experiments with time trial bikes of larger sizes with small 650 front wheels in the pursuit of aerodynamics, they have a smaller frontal aero which is one of the key principles of aero bikes.
Zipp’s new 404 650c Firecrest Carbon Clincher take the regular 404 and downsize it to 650c. The rims 58mm has a full carbon fibre construction and their Firecrest rim shape, the fat rounded shape that has become popular with aero wheels in recent years.
The wheels come with Zipp Tangente butyl road inner tubes with removable core (650 X 18-25mm, 90g), Zipp Integrated Valve Extenders, Zipp Valve Extender Wrench Set, Zipp Tangente Platinum Pro Evo Brake Pads, quick-release skewers and rim strips. Thee freehub is compatible with 11-speed cassettes.
Weight for the wheels is 1465g for the pair (670g front, 795g rear). No UK price yet, but in Euros the front will cost €1,138 and the rear €1,387. They’ll be available in March.
Integration is big in aerodynamics at the moment. The new Zipp Vuka Stealth is a fully integrated aero handlebar design that is fully adjustable. Getting a good fit on a time trial bike is absolutely essential, as is being able to easily adjust your fit in the pursuit of a more aero position. SRAM claims an dizzying 1,920 possible fit options. We wonder if they’ve actually tried every single one of them. We’ll just have to take their word for it.
Central to its design is a truncated airfoil base bar that is within the UCI’s 3:1 aspect ratio specifications. On to this is integrated the stem and mounting hardware for the extensions. All cables are routed internally, maintaining the clean lines. Because the stem is moulded to the basebar, Zipp will offer three stem lengths (short, medium, long) and there’s a a 10mm stem length spacer for fine tuning. Height can be adjusted with 10, 25 and 50mm stack risers which are included.
It’s made from unidirectional carbon fibre with titanium and aluminium hardware to save even more weight. It hits the scales at a reported 820g. Again no UK price but we know it will cost €958. It’s scheduled for a March release, just in time for the time trial season.
David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.