This article first appeared on BikeRadar.
If it was any more aero, it would have to be heavier. Any lighter, and it would be less aero. This is what Specialized says about the new Specialized S-Works Venge, an aero disc bike that will be raced at the Tour de France.
Weighing a claimed 7.1kg for a 56cm bike, with the lightest paint job Specialized offers, the S-Works Venge frame has been paired down to 960g with the fork coming in at 385g. Even the bar/stem has got lighter, down to 440g from 547g. Its predecessor the Venge ViAS weighed 1,200g with a 410g fork.
The bike is a hydraulic/Di2-only machine that comes with a left/right power meter and aero cockpit that is easily adjustable by the rider, including changing stems lengths or even the handlebar.
The Venge cockpit looks integrated to the eye and the air, but the cables and wires run underneath the stem
Built from an aero library
"There is no way to get any of these tube shapes lighter without also becoming less aero, or make them more aero without adding more weight," says Chris Yu, Specialized's director of integrated technologies.
Ingmar Jungnicke, Specialized's aerodynamics lead, says the library was built from thorough modeling and "based on what we know today for materials." That is to say, in the future lighter aero shapes could certainly be possible, but it isn't now, he says.
Specialized claims that the frameset is right on the performance edge — any more aero and it would be heavier; any lighter and it would be less aero
"Optimization means optimal for constraints you have: materials, cost, what is realistic for manufacturing, etc," Jungnicke says.
To demonstrate how much weight was saved from the previous Venge, Specialized physically cut the comparable amount of weight out of a ViAS frame. With a 20 percent saving on the frame and bar/stem, the chopping was substantial.
For a visual comparison, Specialized removed the amount of weight from the Venge ViAS in white that the company saved with the new Venge in black
Of course, the new Venge isn't just a chopped-up bike; extensive modeling, prototyping, CFD and wind tunnel work went into the new design.
Specialized declined to specify drag numbers for the bike, but only says it was faster than the current Venge ViAS.
In terms of ride characteristics, the bike has a whopping 40–50 percent more rear-end compliance than the ViAS, but is not quite at the S-Works Tarmac level of comfort.
Specialized engineers worked with a library of tube shapes, each optimized for aero and stiffness characteristics, to form the 2019 Venge
The bike's geometry is identical to the Tarmac. The frame stack and reach numbers are different on paper from the Tarmac, but in in practice the two are identical as the Tarmac SL6 has a 10mm headset cone and the Venge has a minimum of 18mm of spacers.
The Venge seatpost comes in 0 and 20mm setbacks and in 300 and 390mm lengths. The bike itself comes in six sizes.
Stiff stem, easily adjustable aero bar
Unlike many top-end aero bikes that come with monocoque bar/stem setups, the Venge has separate bar and stem components so riders can adjust the pieces as they wish.
The Aerofly II bar is 235g, and Specialized claims it is stiffer than the Zipp Sprint SL, a favorite of riders like Peter Sagan for its torsional rigidity.
The S-Works Aerofly II bar is quick in the wind, but unlike integrated bar/stem models, can still be easily adjusted for fit
While the Aerofly has internal routing, the hydraulic hoses and Di2 wire run along the bottom of the stem, not inside it. This means riders or shops can change the stem lengths without redoing the shift and brake lines. If riders want to use another 31.8mm handlebar that is also an option. And the Aerofly II works on other road bikes, too.
There are 6-degree stems available in seven lengths (80–140mm) and 12-degree stems in 110, 120, 130 and 140mm lengths.The new Aerofly II bars come in four widths: 380, 400, 420 and 440mm.
The Aerofly II has an out-front metal computer mount made by Bar Fly, which can also take a GoPro or light underneath.
Hydraulic hoses and the Di2 wire run under the stem, which means you can change the bars and or stem without disconnecting the hoses
Finally, there are two aerobar clip-on options that mount on the stem.
Shimano Dura-Ace Di2 9170, plus Specialized wheels, tires and power meter
The bike is sold only as a hydraulic/electric package, with Shimano's top-end Dura-Ace Di2 9170 group.
Specialized parts round out the build, with Roval CLX 64 wheels with CeramicSpeed bearings, 26mm Specialized Turbo Cotton clinchers, Specialized S-Works Power saddle and a dual-sided power meter at the cranks, the carbon Specialized Power.
Not easily seen but valuable — CeramicSpeed bearings and a dual-sided power meter
Specialized says the bike can fit tires as wide as 32mm, but it specs the 26mm Turbo Cottons for their balance of rolling resistance and aero properties.
Specialized S-Works Venge and Sagan Collection pricing
The 2019 Specialized S-Works Venge
The new Venge comes in standard and Sagan Collection models, as framesets and complete bikes. The prices are as follows.
- Specialized S-Works Venge: £9,500 / $12,500
- Specialized S-Works Sagan Collection Venge: £9,500 / $13,250
- Specialized S-Works Venge Frameset: £3,500 / $5,500
- Specialized S-Works Sagan Collection Frameset: £3,500 / $6,250