Aero Road Bikes Square Off: Specialized Venge vs. Cervelo S5
Let me start by saying that my personal road bike is decidedly un-aero. It is metal, has round tubes, box-section aluminum rims, and 32 spokes per wheel. It’s a very nice bike by any measure. But it is not a carbon “wonder bike,” and it is basically the polar opposite of the Cervelo S5 and Specialized Venge. So I jumped at the chance to ride these two bikes to see what the deal is with aero bikes.
The aero road bike market, as I mentioned a few weeks back, is growing quickly. And with good reason. There is a real benefit to decreasing aerodynamic drag when riding—less energy required to maintain a given speed. While I was privileged to hear much of this from a Cervelo engineer recently, some of the basic common refrains regarding bike aerodynamics are as follows:
- The number one force—approximately 80%—that a rider has to overcome is aerodynamic drag.
- About 20% of that drag is comprised of the bike and its components
- For average riders, a savings in aerodynamics trumps a savings in weight on any terrain up to a 5% grade. In all other situations (flats, downhills, and shallower climbs) the aero benefit wins.
Those and other statistics aside, the real question in my mind was, “why not ride an aero road bike?”
Cervelo S5: So very fast in a straight line, polite handling manners
The Cervelo S5 comes in a standard frame, a “Team” level frame (100 grams lighter), and a “VWD” level frame (Vroomen White Design—the lightest/stiffest available with technology gleamed from their Project California work). Complete stock bikes are available with SRAM Rival on the standard frame, Ultegra or Ultegra Ui2 on the Team frame, and Red or Dura Ace Di2 on the VWD frame. As you might guess, the price goes up as the frameset gets lighter and stiffer and the components get even nicer. (Let’s face it, the parts kits start off pretty nice.) The S5 that I rode was straight out of the shop’s rental department (thanks, Stephen and crew!), which meant I was on the Team frame with an Ultegra build.
When I got the S5 home I started to really look the bike over. It is clear when looking at the S5 that it is an engineer’s bike. Aerodynamics was priority one for the S5, and no concessions were made for “style” or marketing—a fact that Cervelo’s engineer flat out told me. I’ll say it now; I’m not a fan of the tube shapes on this bike from an aesthetic point of view. Independent testing done in a recent issue of Velo shows that the S5 is the fastest in the wind tunnel, but that doesn’t mean mass aesthetic appeal. Lucky for everyone, that’s a personal thing. I didn’t love the bike’s shape, but I’m one of the folks that actually likes Cervelo’s paint/graphics packages. Another subjective point, but I personally like the simpler paint.
The S5 features much of Cervelo’s top-shelf technology, most notably their BBRight bottom bracket design. Utilizing a 30mm aluminum crank spindle, made 11mm longer on the left side, the BBRight system allows for the biggest possible tube juncture interface for all tubes that connect at the bottom bracket shell (chainstays, seat tube, down tube). According to Cervelo, it is tube size and shape, and thus the frame, that provides the biggest drivetrain stiffness gains compared to just crankset choices. Even in their aero form, the tube shapes on the S5 are simply massive and lend to the bike’s notable stiffness—more on that later.
I did have to scratch my head on a couple of the parts choices for the stock builds. The S5 is billed as a no compromises, hammering off the front race bike. As a result, I question the use of the compact crankset. I suspect I know why the decision was made to use a 50/34 ring combination—to make the bike more appealing to more riders—but racers will likely want a standard crankset and that should at least be an option on every stock build offering rather than not offering a standard ring combination until the $7500 VWD frame/SRAM Red model. After all, there isn’t really a huge secondary market for BBRight compact cranksets, particularly as no other bike manufacturer has yet to adopt the open BBRight design.
The other thing that had me wondering some was the wheel choice. Fulcrum (part of Campagnolo) makes a fine hoop, but their base level wheel on a no-holds-barred race bike is somewhat troubling. Again, I suspect I know why this is done—to control costs and running on the theory that most folks getting this bike have or will get their preferred race wheels. That makes some sense on the highest end bikes. But a racer looking to get a race bike out of the box, would be better served with a nicer wheelset. The stock Fulcrum whoops are decidedly un-aero and quite heavy when compared with other even entry-level race wheels. Noticeably, pictures of the S5 bikes on Cervelo’s website show different wheels on the bikes.
Setting the bike up with my preferred fit was almost fool-proof. The clamp for the aero seat post was simple to use and easy to adjust. Saddle setback was easy as well with a saddle rail clamp that adjusted simply and quickly. The front of the bike was more difficult. The S5 features a very tall head tube—nearly 18cm on the size 56cm bike I was on. There is an engineering reason behind this. The longer head tube allows for a dropped down tube, which smooths airflow from fork to frame and actually stiffens the front end as stresses are more easily transferred from the head tube to the down tube. Still, it made getting my preferred drop difficult to say the least. Even with the -17 degree stem I could not quite get my bars to the height I normally run them. For test riding purposes this was ok, but again, for a top-end race bike the fit should, in my opinion, err on the side of letting folks get low easily.
Looked over and dialed in I took the bike for a ride—and fell in love again. I say again because I owned both the 2010 and 2011 iterations of the Cervelo R3, the 2010 being one of my favorite stock bike models of all time. The S5’s handling immediately reminded me of those bikes as I cruised my neighborhood loop, taking turns no handed and easily looking over my shoulder without any noticeable drift to the side. The handling also shone through when I took the S5 out to the Driveway. The bike’s predictable manner on the Driveway’s sweeping turns made it a joy to put into a lean. And the bike’s massive tubes made it stiff—very stiff. Not at all a problem on the racetrack’s smooth surface, but on Austin’s rougher roads the bike’s back end felt a little like it was trying to buck me off. Again, my day-to-day road ride that I’m most used to is a markedly different bike, but if the S5 handled like the R3, it certainly didn’t have the rough road manners of the cobble crushing R3 or my daily driver. The other minor thing for me was that the tube’s massive shapes echoed drivetrain noise. For my money, I like a bike that’s silent but for the click of my shifter.
It was easy to forget though about being off a centimeter on my preferred bar height, wishes for a “perfect” stock build, or the bike’s looks when I wound it up. The bike screams to go fast. It’s impeccable handling aside, the bike is like having a set top-shelf aero wheels on an otherwise un-aero bike. It’s like a free gear. Put another way, and as I’ve mentioned before in an aero wheel review, it’s as if you’re normal cruising speed bumps up a mile per hour or so without any added effort. The S5 is like buying speed. And that’s the whole darn point of the bike—to go fast. It’s not built to meet everyone’s aesthetic requirements, aesthetic wishes, or ride-quality desires. The S5 is an engineering exercise with the goal of going fast. Goal achieved.
The Specialized Venge: A race bike that starts cheating the wind.
Specialized offers the Venge in no less than seven stock models and two frameset options. Complete bikes start with the standard frame and Ultegra, Red, Dura Ace (mechanical), or Ultegra Ui2 builds. There’s an S-Works frame with either Red or Dura Ace builds. And then there is the McLaren (yes, that McLaren) S-Works bike with Dura Ace Di2—let’s just say $18,000 and leave it at that. True to the typical Specialized line of road bikes, as you go up the frameset scale, you get stiffer and lighter, with the McLaren bike being the pinnacle of the Big S line-up. I got a call from the shop’s bike buyer telling me that the local Specialized rep dropped off a demo bike for me. When I got there, I saw it—an S-Works SRAM Red Venge. Um. Ok!
Like the Cervelo, I take issue with the Venge’s appearance. I rode what’s called the “white/neon red” colorway. From an inventory standpoint, I get why large-scale manufacturers limit color options, but from a consumer point of view, I want my bike to look the way I want it to look, particularly as the bike heads to the North end of the price range. I was drawn to the Venge’s tube shapes, but the paint left me a bit dizzy. Too much for my taste. Again though, this is probably inconsequential as bike aesthetics are a highly personal matter. For an out of the box bike there are, in my opinion, better looking graphics packages. Again, too each their own.
Specialized bills the Venge as a marriage between the performance of the venerable Tarmac and the aerodynamics of their Shiv TT/Tri bikes. This is apparent in the shapes found on the bike, most notably in the top tube/head tube/steerer interface as well the seatstays. The front end of the bike seems almost all Shiv and the back end seems almost all Tarmac. Of course, when you’re talking S-Works, you’re talking about Specialized’s highest end carbon construction method with the highest end frame material to boot. I couldn’t help but notice that the while tube shapes looked aero, they didn’t seem to go to the extremes that the Cervelo did. The seat stays and the rear wheel cutout in particular looked sort of “old fashioned” compared to the obviously aggressively engineered for slicing the wind Cervelo tube shapes. Riding the bike would tell that story.
The build on the S-Works SRAM Red bike was pretty straightforward. A full SRAM Red drivetrain, save for the Specialized S-Works carbon oversized bottom bracket crankset. Specialized is very proud of this crankset, and rightfully so. It’s light, stiff, and many riders sing its praises. My test ride also came with the stock Roval Rapide 45 wheelset. All of the Venges in fact—save the McLaren—come with Specialized’s house brand hoops. While not particularly light, or renowned for cutting edge aero tech, the Roval aero wheels offer noticeable benefit with their carbon fairing mated to aluminum rims. While decidedly older than some other aero wheel technology out there, the formula is proven and offers superb and perhaps most importantly, predictable braking performance. (The McLaren rolls on Zipp’s venerable 404s, albeit in the newer Firecrest—read: wider rim bed, rounder nose—shape).
The build was respectable, if not remarkable, which lead to my biggest problem with the Venge—price. With a suggested retail of $8,800, the S-Works SRAM Red Venge is a very expensive Red equipped bike. Yes, you’re getting a top shelf frameset. And yes, you’re getting wheels beyond the budget ones found on the Cervelo. But still, $8,800 when an S-Works Tarmac with the same grade of carbon tubing and same construction method and a Red kit runs $7,700, seems particularly steep. I know what you’re thinking: “this guy’s quibbling over $1,100 when talking about bikes that are closing in on $10,000.” But I still contend that when spending money like this, you should get remarkable. And for the extra $1,100 I’d like to see, well, more. Maybe Zipps. Maybe a power meter of some sort. Something more than aero tube shapes and slightly taller carbon fairings on the wheels. On this measure alone, for my aero road bike money, I’d skip the S-Works and get the Pro model with Ultegra Ui2 and keep $2,200 in my pocket—or maybe buy a power meter—and get the same tube shapes and what some are saying is better than Dura Ace Di2 drivetrain performance.
Setting up the Venge with my preferred fit was a breeze. The seat post clamp was again easy to use and adjust. The post itself is reversible giving a traditional set back position or a zero offset position. The saddle clamp was a little troublesome. I had problems setting the saddle level; each time I adjusted the saddle’s angle and tightened the bolt, the nose would angle down. I had to wrestle with the seat some to get it close to level, which is how I like the otherwise excellent Romin saddle. Bar positioning was a snap, and I could get my drop set easily, but I did have some trouble with my cockpit reach once my saddle setback was set, but that’s nothing a 20mm longer stem wouldn’t fix. Since it wasn’t my bike, I decided not to go trade in the stem for a 120mm one.
I also took the Venge to the Driveway—twice. (Show up to the Driveway one week on a Cervelo S5 and the next on a Specialized Venge and folks start to wonder if you’re holding the winning mega millions lottery ticket.) The Venge’s first trip was for the first Super Squadra Skills Clinic of 2012 and then a few days later to race. I was glad to get the chance to ride the Venge at speed in a controlled setting first as its handling seemed decidedly faster than the S5’s. I always say that I like fast-handling bikes, then I get on one that has even slightly faster handling than my personal bike and think “whoa, slow down!” I’m not sure why the handling was faster with many of the frame dimensions the same as the Cervelo. It might have been the shorter cockpit or how I was balanced on the bike given the slightly shorter overall wheelbase. Whatever it was, I had to pay a measure more attention to the Venge in a turn, but it was easier to change lines once aiming for the apex started.
The bike didn’t feel nearly as stiff in terms of ride quality than the S5. This was a welcome change for me. The back of the Venge never felt harsh regardless of the roads I rode it over, which gave it a sense of familiarity relative to my personal bike. And the front end felt good too, resisting twisting forces when I was yanking on the bars on the back of the 3/4 race at the Driveway. All-in-all I liked the ride quality of the Venge quite a bit. As for its “aero-ness,” it had that same kick-in-the-pants feeling as the S5. Getting up to speed and holding it at an easier effort level was again the hallmark of the bike. What was harder to tell here was whether it was the bike or the bike and it’s wheels that gave it that feeling. Seeing as how any aero advantage is an advantage, I’d say it was both and it was welcome whenever the pace went up.
My takeaways on aero road bikes and the S5 and Venge in particular
I took to the Cervelo initially because I had such fond memories of my past R3s. I wanted to love the S5 as much as I had those bikes. But for me, where all around ride quality is king, the S5 didn’t quite live up to my dreams. And, trying to think as a potential purchaser of an S5, I still had the constant “I wish…” items running through my head. In the end, as someone that would buy a stock race bike, I can’t rationalize one without race wheels, and I can’t justify a higher-end bike just to get traditional 53/39 gearing. But the bike rode really, really well particularly in turns and of course in terms of top end steady tempo efforts in a straight line. Like some of the best aero wheels, the S5’s wind cheating characteristics shined though. If flat out speed—all other things be damned—is the goal, then the S5 is worth a serious look.
As for the Specialized, I’ve only ever ridden an older Roubaix, so I can’t give a direct Tarmac comparison, but the Venge felt like a race bike. It was fast handling and had refined road manners across nearly every road surface. It too felt like it sliced the wind, but not as fiercely as the Cervelo did. And it was built like a race bike with a 53/39 crankset and aero wheels, albeit basic ones. Still, I couldn’t help but think that the bike was simply a little too expensive as built. The Ultegra Ui2 Venge seems like a much better aero road bike buy, or of you really want that S-Works badge and SRAM Red, then the Tarmac in the same livery still leaves you some cash for a BG Fit and some new proper fitting kit, or maybe some aero wheels. Build kit options notwithstanding, the Venge’s winning ride quality mated to its aero properties make it the better all around race bike for me.
For sure both bikes felt aerodynamic. They gave the same sensation as aero wheels on a traditional bike, which is to say they both felt like they went faster, easier. As mentioned, the Cervelo has tested faster in the wind tunnel. In fact, it was top of the class in that regard. Tube shapes on par with their top-tier P5 tri rig and some of the cleanest, if not easiest to route, cable routing have a lot to do with that. The Venge was a better all around bike that happened to be aero in my opinion. And that aero sensation seemed admirably helped by its stock deep wheels, but it also felt good on rough roads. Those same tests that put the Cervelo on top for cheating the wind, bear this out as well as the Specialized didn’t test as stiff in the rear end. If the Venge is “more bike than aero” I’d say the Cervelo is “more aero than road bike.” At least with me in the saddle.
While I had issues with the aesthetics of each bike, others in my bike-racing circle of friends and acquaintances, on the whole, took to the two bikes differently. The S5 drew a few odd looks and some questions about triathlon. For folks drawn to the Venge, there was basically one response: “nice bike.” This struck me as odd as both bikes are built, presumably, for this very class of rider: the dedicated road racer. Perception in the marketplace, it seems, is something of a driver for many road racers. Folks saw the Specialized, generally, as a road bike and the Cervelo as a tri bike with drop bars. While this is obviously not the case, this is what many thought at least in terms of impression. Looking around the early season road races, I can say I’ve seen many Specialized bikes and many Cervelos. And while I’ve seen some Venges under riders, and a few of Cervelo S3s, I’ve not seen any S5s save the demo bike I was on.
There’s no doubt that either of these bikes, like other aero equipment out there, offer riders a real-world benefit. Added together, proper fitting kit, aero wheels, a fit that lends itself to a narrow but comfortable and maintainable riding position, and yes, even an aero road bike will all help beat the force that we’re primarily working against when riding—aerodynamic drag. The question for any rider considering a higher end race bike is why you wouldn’t consider an aero road bike. Given a “traditional” race bike versus an aero one at the same or similar price-point or with comparable tradeoffs and the aero bike is like getting an added feature for nearly every riding terrain included with the purchase. I am beginning to wonder if it might not be time for an aero upgrade of my own.