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June 23, 2015
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
I’m sometimes told that I’m a marketer’s worst nightmare and don’t buy into technical claims or emotional techniques. So when Specialized claimed that riding their Venge ViAS and other aero equipment would save 5 mintutes over 40 kilometres, first question was, “where are the asterisks?” The numbers might stack up in theory in the wind tunnel, but I want proof that this translates into the real world.
Specialized anticipated this and wanted the small group of journalists who attended their private launch to experience their claims and return home without any doubt.
I was given the opportunity to have some wind tunnel testing performed on me to collect baseline aero-mapping, and then taken out into the real world to see how much quicker the Venge ViAS, Evade Helmet, and skinsuit combination were over a comparison of a “traditional” equipment set-up.
Unfortunately going out and timing yourself on the same course with two different equipment set-ups is too simplistic a model to be able to prove anything. There are just too many variables. This is where McLaren comes in.
Midas (McLaren Integrated Data Analysis & Simulation) is McLaren’s in-house software suite developed specifically for their own F1 testing and performs mathematical simulations and analysis to allow virtual test-runs of any given track and equipment combination. Two McLaren engineers made the trip from the UK to Morgan Hill to apply their Formula 1 expertise in helping us compare a “traditional” equipment set-up compared to an “aero” equipment set-up.
One of the biggest differences between F1 and cycling is that 40% of the simulation for F1 comes down to one overwhelming variable: tyres. Things like aerodynamics (except for generating down force) don’t come into play when a powerful car is travelling 250km/hr against a 40km/hr wind. However, in cycling, approximately 80% of the simulation comes down to aerodynamics (up until a point where the road begins to rise and gravity starts taking over).
What the McLaren engineers were here to do was to use the Midas software to help collect our real-world riding data, normalise all the variables between two equipment set-ups, and precisely determine which was quicker.
Aerodynamic wind mapping of the two equipment set-ups. Left: the “Traditional” set-up using a Tarmac, Roval 40mm carbon wheels, typcical kit, Prevail helmet. Right: “Aero” set-up using the Venge ViAS, Evade helmet, Evade Skinsuit.
I own a Tarmac very similar to the “traditional” equipment set-up that we were comparing the Venge against.
My kit set-up was also similar to what I’d normally ride. A race-fit jersey, regular helmet, and my regular shoes (they didn’t have new the S-Works 6 shoes for us to use which Specialized claimed to have up to a 35 second aerodynamic advantage).
It’s an equipment set-up that I’m comfortable with and I’ve never considered myself to be disadvantaged by any of it. I’ve always been sceptical of aero helmets, aero bikes and anything else that’s marketed along these lines and have never considered them on the premise that they’re quicker.
Most of the other journalists who did the testing tried to keep a similar power output between the two rides. But me, I thought I’d try to trick the simulation. During my traditional set-up ride, I averaged around 150 watts. A nice easy roll. On my second ride, I went relatively hard at about 300 watts for the entire 19.2km.
We had a good variety of conditions to play with: moderate winds at a variety of angles (due to the course direction changes), some good flat roads, short descents, and punchy climbs.
One thing I must admit while riding the Venge ViAS, especially with this back-to-back comparison, was that this bike immediately set the impression that it was incredibly fast. Of course I was also dressed very aerodynamically which would have had something to do with it, but there was a tangible difference when pushing the pedals on this bike that I can’t recall feeling before.
The most noticeable difference was when the bike was hit with a crosswind. The entire machine felt like it turned into a sail and actually picked up speed rather than unpredictably fighting against it.
The other impression this bike made was how remarkably quiet it was (aside from the “whoosh” of the wheels when accelerating). It had this intangible sound of aerodynamic efficiency that I can’t recall experiencing on even a top-end TT bike.
There wasn’t a huge difference between the handling and comfort characteristics between the Tarmac and the Venge ViAS, which was a good thing. I prefer the ride qualities of the Tarmac over the legacy Venge, and I welcome the changes.
You’re probably wondering about how the brakes performed. That was the burning question in my head as well. Some aero bikes I’ve ridden have sacrificed braking performance for the sake of aerodynamics. Specialized engineers claimed that Shimano Di2 dual-pivot brakes were the benchmark performance that they designed to.
During my two rides on the Venge ViAS, I didn’t notice a degradation in braking performance (however, we never had wet weather to contend with). The set-up and maintenance looked straight forward and it’s quite a simple system, but we’ll report back with some more extensive testing later in the year.
So, how did the Venge ViAS stack up against its claims of being able to save 5 minutes? I’ll cut straight to the chase. I saved an accumulated ~143 seconds (2:22.5 minutes) with a ~2km/hr increase in speed over the 19.2km course. Over 40km, that’s 4:45 minutes (on a course which included 1km of climbing), and I didn’t wear the new S-Works 6 shoes which have a claimed time saving of 35 seconds compared to the shoes I was wearing. It didn’t matter which power profile Midas normalised the numbers on, both came to the same conclusion.
Midas screenshot showing the various parts of the course where aerodynamics made a difference. Blue = aerodynamic configuration, Orange = traditional configuration
Midas screenshot which shows the time savings at a given point on the course. (course data such as map and elevation at bottom)
Between the 12 journalists who were put through the testing, the average time saving over the 19.2km course was 120 seconds (2 minutes) and 2km/hr.
Playing with Midas – Some interesting tangents:
Of course Midas wouldn’t be much good if we couldn’t tinker around to see what effect the different variables had on the overall time using the course data we had on hand. Here are a few things I found interesting:
Weight variables: Reducing 400g on the traditional setup saved a total of 9 seconds over the 19.2km course. Six of those seconds were gained on the climb, which was only 400m at about 6%. However, reducing the aero drag by the minimum that can be measured (i.e. adding 0.002m2 CdA – the equivalent of a cable housing exposed) will add as much time as around 400g weight difference.
Power variables: When adding 10% rider power output to the traditional setup, the aero setup was still 45 seconds quicker over the 19.2km course. Adding 15% power output in traditional setup, the aero setup was still 2 seconds quicker. Most of this time gain results from the short climb.
Rolling resistance variables: Adding 25% more rolling resistance to the aero setup slowed the simulation down by 36 seconds (which is equivalent to a high-end race tyre compared to a cheap training tyre).
Conclusion: aero really is everything.
You can download the full summary of the test protocol, course maps, Midas simulation graphs and data here (pdf).
For a thousand dollars, an aero helmet and skinsuit will shave off nearly half of the 5 minute message. That’s true, and it highlights the enormous gains that can be easily made, validating Specialized’s aero obsession. For those who can afford it, there’s another 120 seconds just waiting to be bought.
Specialized is often criticised for their over-the-top marketing but the time they took to prove to us the performance gains they’re striving towards through aerodynamics was well and truly beyond what I’ve ever experienced. With a simple powerpoint presentation and a quick ride of the bike, I would never have believed the claimed benefits of their offering.
This time, their “over-the-top” efforts to prove the aerodynamic advantages they’ve achieved with our own legs providing the data went far beyond what their marketing department could ever do.
Head over to this post for a closer look at the Venge ViAS and full explanations of its features, specs, pricing and availability.
Full Disclosure: We would like to thank Specialized for hosting our visit to Morgan Hill, CA and providing us with this experience. Specialized has been a long time advertiser with CyclingTips.