The Crucible: Tarmac vs. Roubaix

IMG_0447The final switchbacks of Malibu’s Decker Canyon Road

After months of riding on both the Roubaix and the Tarmac SL I was dismayed. I had yet to determine a preference relative to my own riding and that was killing me. Mind you, I wasn’t trying to determine the better bike, because I didn’t actually think one was superior to the other, but I believed that because the two bikes were different I must, as some point, arrive at a conclusion about which better suited my taste. Simply put, I should get down a technical descent on one faster than the other. Which would it be?

Malibu contains more than a dozen roads that run from the ridgeline of the Santa Monica Mountains down to Pacific Coast Highway. The roads can drop nearly 2500 vertical feet at grades of up to 18 percent. The descents generally range between 4.6 and 9.2 miles. Most of them feature more than a dozen turns per mile. At 40 mph, that’s a turn about every six seconds … and many of the turns can last for three or four seconds.

Of these descents, three offer grades steep enough to sustain speeds above 45 mph over road surfaces that don’t make the experience seem like fodder for an episode of Jackass.

Kanan Dume Road recalls the sweeping turns and consistent grades of the Rocky Mountains. It features far fewer turns than the other descents and a good deal more traffic.

Tuna Canyon Road is where the ill-fated Red Bull Road Rage was held. It features more than 70 turns in 4.2 miles and drops some 1800 feet at an average gradient of 8.1 percent. On the descent’s one significant straight (which was used for the speed trap in the Red Bull event), it is possible to clock 60 mph just before a sharp left turn will cause you to rethink your actions or alter your future. I know plenty of riders afraid to descend this road and it’s one of a handful of roads I descend where I’m unwilling to let the bike run. The looming wall of dirt has whispered things to me about deceleration trauma that I’m unable to repeat.

Decker Canyon Road is a bit like Tuna Canyon light. It is almost a half mile longer, drops 150 fewer feet, culminating in a 6.8 percent average gradient, as compared to Tuna Canyon’s deceptive 8.1 percent average. It also features nearly roughly ten fewer turns, meaning the road bends don’t come quite so frequently.

Decker Canyon is my road of choice for challenging myself on a descent or when testing the limits of a bike’s cornering. The descent is fairly steep, but not super-steep, the turns come in rapid succession and nerves of steel are tested in the turns, not in the chutzpah of straight-line speed.

I came up with a crucible. I’d take both bikes up to Malibu. I would ascend Encinal Canyon Road six times—three times on the Tarmac and three times on the Roubaix—and following each five mile, 6.3 percent average gradient ascent of Encinal Canyon I would plummet down Decker Canyon.

My first two ascents of Encinal were aboard the Tarmac. The second two were aboard the Roubaix. Trip number five was back on the Tarmac and the final trip was made aboard the Roubaix. The six circuits only added up to 57 miles, but the climbing totaled more than 9000 feet ascended.

My position was very similar on both bikes; saddle height and setback was the same and reach to the bar was within a centimeter, though the bar on the Roubaix was almost a centimeter higher. Switching between the two was unremarkable from a position standpoint. However, as soon as I did switch from the Tarmac to the Roubaix the increased vibration damping was immediately apparent.

According to my GPS data my fourth and fifth ascents (Roubaix and Tarmac, respectively) were my two fastest; my average speeds were within a tenth of a mile per hour of each other. Interestingly, I burned fewer calories on the Roubaix, lending further credence to the idea that cutting vibration can decrease fatigue.

My three fastest descents were aboard the Tarmac. On those descents (first, second and fifth) my max speed was 46, 46 and 46.5 mph, respectively. My slowest descent, surprisingly, was my first trip down on the Roubaix.

The tightest turns on the descent, the ones on which there was no question of braking, just how hard would be necessary, were all right-handers except for the final switchback less than a mile from the bottom. I was able to carve very consistent lines through these turns and found myself consistently shaving the yellow lines on the Roubaix and six inches to the right on the Tarmac. That minute difference made a big difference at speed.

What I noticed was that the more I felt like I was really having to manage the bike—push it—to negotiate a turn, the more inclined I was to brake before the next turn. I did almost no braking during turns on the Tarmac but did scrub speed with some regularity during turns while aboard the Roubaix.

A brief word on my descending: Fast. I like it. Roller coasters were always my favorite at amusement parks when I was a kid but today, compared to mountain roads, they lack a critical interactivity component. That said, I don’t take what I believe to be are risks. While I find the foregone conclusion of a roller coaster lacking, I enter every turn with the belief that my safe exit from it is deal-done. As soon as I feel like I’m really pushing a bike, I back off. My empiricism ends at the point of wondering just how fast I can enter a turn and exit it without a yard sale. Aided by downhill pads and a Kevlar suit I might play my hand differently and bluff my way straight to call, but in Lycra I do little more than ante up.

What I learned was I preferred the Tarmac for descending. I’m unafraid to declare my surprise at this. I really thought that the Roubaix would see me brake less and roll up to higher speeds, but it just didn’t happen that way and I can say that I did my best to make each of those drops an E-ticket ride.

But how many people buy a bike for how it descends?

In my estimation, more bikes ought to be purchased that way. I think it indicates a great deal about a bike’s character. A downhill turn is the ultimate litmus paper for any bike. If the bike won’t turn, you should ask yourself what that bike is meant to do and what you plan to use it for.

But here’s the asterisk: My preference for the Tarmac was revealed under fairly extreme circumstances. Most riders won’t ever ride down a road as challenging as Decker. There just aren’t that many of them in the world and unless such a road is part of one’s regular vocabulary of roads, the reasonable response is to back off. So what about the downhills more regularly encountered? What if, say, you rode in the Rockies or the Alps?

If I factor Malibu out of the equation and consider the other roads I took the bikes over, the many other roads I’ve ridden around the world, the answer is easy.

The Roubaix is easily one of the best all-around bikes I’ve ever ridden. I’ll venture to say it is one of the best thought-out bikes on the market. For most riders under most circumstances the Roubaix is an easy correct answer. It’s lighter than elfin armor, handles with the relaxed control of a Bond villain and cuts vibration like a power outage.

The Roubaix should be the default answer for anyone considering a Specialized road bike (or perhaps many other road bikes).

So where does that leave the Tarmac? It is, without marginalizing it, a bike for the margins. The Tarmac is the Navy SEAL to the Roubaix’s sailor, the surgical scalpel to the butcher knife, the truing stand to the Y Allen wrench. It is the accept-no-substitute for criterium racing, intestinal descents and the most aggressive group rides.

They are both spectacular bikes and well-enough differentiated to have earned their place in the Specialized product line.

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  1. maxrad

    I note that– according to Specialized, anyway– some team riders preferred one or the other depending on the course that day. Others just preferred one or the other. Having ridden both, I agree they’re both fine bikes; which is better is purely a matter of personal choice.

    I would suggest that being 1cm lower on the Tarmac would help you corner faster, too. But since that extra cm is built into the Roubaix design I still think the test is fair.

    OTOH, you didn’t track your climbing speed? I would guess that particularly as you got tired, the stability of the Roubaix would tell in its favor.

    1. Author

      Maxrad: Yes, I was told that when the company was sponsoring Gerolsteiner, some of the riders ended up riding the Roubaix for the whole of the season. Not sure about the other teams. I do think if you could lower either bike to 8cm of drop you’d really be able to scream down descents, but this is just guesswork on my part. My climbing speed was tracked but Encinal Canyon winds very lazily; holding my line wasn’t an issue on that road due to its construction and the fact that I was tired, but not that tired.

  2. Josh Kadis

    For what it’s worth, Tom Boonen and a few other riders get custom frames with a Tarmac front end and Roubaix rear triangle for the cobbled classics. From Padraig’s experience, maybe that’s the best of both worlds.

    1. Author

      Everyone: Thanks for the terrific comments. It’s a relief to hear that my experience so closely resembles your own.

      Josh: I hadn’t heard that; I was under the impression from the bike I saw (one of Boonen’s back-up bikes) that he was on a pure Roubaix at Paris-Roubaix. I’ll have to ask for more info from Specialized.

      Elliott: Just to be clear, my first descent on the Roubaix—which is was my third descent of the day—was slowest. I’m with you; I would have expected my first descent to be the slowest overall, but that wasn’t the case. My first descent—which was on the Tarmac—was tied for second fastest, certainly not something I expected. Frankly, I was shocked.

      Touriste-Routier: I have taken the Tarmac down Tuna, but I can’t recall if I ever took the Roubaix down Tuna. In the last eight years I can recall two descents that made me nervous: the west side of the Col de Marie Blanque and Tuna Canyon. The Tarmac on Tuna Canyon makes it just another day in the saddle. The big thing about Tuna is to make sure you descend with your cranks level so that it is as easy as possible to shift your weight from one side to the other. As soon as you drop a pedal it becomes much harder to shift your weight and you end up braking a great deal more in order to get around a turn. Had I hit Decker at mile 96 of a ride one thing is certain: my max speed would either have been much higher or much lower than 45. Hard to say which. Either I would have cared too much … or not enough.

  3. MattS

    Fantastic. Lets hope the word gets out that comfortable road bikes like the Roubaix are fast, and race bikes like the Tarmac really are best suited to aggressive riders, not the average Joe or Jane. Perhaps we’ll see more people stick with riding if they are on bikes that feel good and are built for the riding they actually do. I sure would be interested to feel a Roubaix with 8cm drop too….

  4. Geoffrey Clark

    I spent this year splitting my time between identically equipped (D-Ace, Mavic Ksyrium SL) Tarmac SL and Roubaix SL bikes. My Roubaix was set up with the stem horizontal and deep-drop bars, so that my position for sprinting was identical to the Tarmac, which had shallow-drop bars. My conclusion: they are radically different bikes.

    I love the comfort of the Roubaix, and it was a natural choice for any ride over 2 hours. What I didn’t love was the longer chainstays, which made sprinting seem sluggish. Handling was reliable, and it was easy to relax and enjoy the ride.

    The Tarmac was always exciting to ride. Much greater lateral and torsional stiffness makes that bike corner better than any other bike available. Essentially, your wheels stay in the same plane as you lean into a turn at high speed, so you can trust your bike to go where you point it. The short, stiff chainstays provide instantaneous response when sprinting – it’s blistering fast.

    As far as comfort was concerned, the Tarmac was fine, and I logged many hilly 100-mile+ days on it. One sweet perk of the incredibly stout chainstays and bottom bracket shell is that the increased strength in those areas allows Specialized to outfit the Tarmac with thinner and more compliant seatstays. I’ve ridden the S-Works SL2 several hundred miles, and logged a couple of hilly rides on the new SL3 Superlight, and these bikes come even closer to the ultimate balance of comfort and performance. Nothing I’ve ridden from Cervelo, Cannondale, Giant, Seven, or Trek even comes close.

  5. Greg H

    excellent job on the review! i work for a specialized dealer and having ridden both bikes many, many times i believe this to be the most concise and well thought out review on a stand alone and versus basis. we can all read a thousand consumer, industry magazine and chat-around-the-coffee-machine reviews and not get this much information without overwhelming the average cyclist or even non-cyclist. i will be using this site as a reference to customers when explaining the differences in experience that each model has to offer and of course, keep up the awesome work!

  6. Touriste-Routier

    Padraig- Somehow I knew your final comparison would be based upon Decker Cyn! Knowing that road all too well, I am not surprised by the results or your opinion. That road is a great proving ground, and your comments are valid and fair nonetheless. Do you think the results would differ if you were doing the final descent after another 40 miles in the saddle?

    I’d love to see the test repeated on Tuna Cyn, but can I take a life insurance policy out on you first? I suspect the results would be even; that is one road where in some ways the climb is easier than the descent, as you get exhausted due to white knuckle brake hand fatigue 😉

    Thanks for the great series of articles. My local Specialized dealer plans on linking to them!

  7. Adam

    “Josh: I hadn’t heard that; I was under the impression from the bike I saw (one of Boonen’s back-up bikes) that he was on a pure Roubaix at Paris-Roubaix. I’ll have to ask for more info from Specialized. ”

    I beleive that Boonen didn’t like pre-2008 Roubaix’s because they didn’t have the snap that he wanted. The confusion over this point is that the “pure Roubaixs” of 2008-2009 are what specialized developed where the front triangle does have a lot in common with the Tarmac. What Tom rode the last two years was stock.

  8. JimB

    Owning both 2006 S-Works Tarmac and 2006 S-Works Roubaix, I feel qualifed to comment on these reviews. I live where it is flat and prefer the Tarmac there. It’s a great bike and good ride and handles well in group riding situations. Also sprints well. I also travel frequently to Colorado and Europe where I ride in the Rockies, Alps, Dolomites. For these trips I take the Roubaix which, to me, is the best descending bike out there. And I also prefer the slightly higher bar position for climbing. I have removed all the spacers and have the bars slammed to the top of the head tube. The Roubaix is quite easy to keep tracking straight on a long, slow climb in Europe. However, my ideal bike would be a Roubaix with a 1-cm shorter head tube to allow a slightly lower bar position for the flat riding aero-important days.

    My standard recommdation to anyone looking to buy a road bike is to buy a Roubaix unless the person has a racing background and really needs the shorter wheelbase and steeper head angle. For most riders, the Roubaix is almost a perfect design.

  9. Craig

    Now that the thesaurus has been exhausted of its superlatives in order to describe these 2 bikes, I have a question.

    Is there anything you do not like about the bikes?

    I agree that specialized make some really good bikes, but I am yet to ride a bike that is without a single shortcoming. If you have mentioned anything critical of these bikes, I am must have skimmed over it. The wheels, for one, are not well thought of. All I know who have purchased bikes with roval wheels have assigned them to the trainer or the spares shelf. I have heard that you are also locked into the specialized crank. Is this true? I have heard that it is set wider than the bb30 standard, which may be an issue for some, especially those who like particularly long or short cranks. What lengths are the specialized cranks available in?

  10. Adam

    Craig, I don’t know if that is a fair assesment of Roval wheels, the hubs are made by DT Swiss, and the rimes offer good braking. There be better wheels out there, but criticism of DT Swiss products in general is pretty rare.

  11. Alex

    I agree with Adam. I liked the Roval Rapide SL that came with my SL2. They´re light and stiff in the range of the Ksyrium ES, perhaps a bit lighter especialy in the rims, made of carbon. I´ve used them for both training and racing without any complaints. Hubs are high quality of course, certainly not prone to failure or any other problem, and they spin smooth. Spokes are easy to find and replace, though I´ve never had to touch them (I´m 75kg and not very rough on equipment). Sure, they´re not “aero” as, say, the 404s. But hey… they look nice on the bike, even more so after removing those flashy stickers :-p

    1. Author

      Everyone: Before I respond to each of the questions raised here, I should make clear for those of you who aren’t already aware, when I review a bike, I review the bike essentially on the qualities of the frame and fork. I’ll address my ability to achieve proper fit, but I don’t tend to spend much time on the group, the wheels, etc. I plan to do a review of the Dura-Ace 7900 group once I’ve had a chance to get a few more miles on the Dura-Ace brakes and crank. I will address to a limited degree components that are peculiar to the manufacturer, such as the S-Works crank, the Roval wheels etc., but I think a bar review should be a bar review and a bike review should be a bike review. I know I’m unusual among reviewers in this regard, but I think a manufacturer should only be held accountable for those items under its control. The whole of the bike, including the group should only come into consideration when evaluating price and, ultimately, value.

      Craig: It’s important to note that there’s a big delta between not liking something and believing something can be improved upon. For $5000, I’m not sure you can reasonably expect much more than what these bikes achieved. I think there are minor points that can be improved upon and the score reflects that. I encourage you to ask yourself this question regarding a bike’s shortcomings: Is the supposed shortcoming an ideal you hold all bikes to or is it truly something that falls below the industry standard for that price point? There are wheels I’d rather ride than the Rovals the Roubaix was spec’d with, but those wheels were included with that bike for a particular reason. To be fair in a review, it is terribly important to consider the intent of the design and not just personal preference. It may be that lots of people don’t like that wheel; it could be equally true that lots of people simply want a lighter wheel. I found the Rovals to be bomb-proof. I took the bike over some nasty roads and to this day they don’t need truing. That said, I’ve got review wheels here that have fewer than 200 miles that have loose spokes. The BB on both bikes is 68mm—industry standard. I am aware that the S-Works crank, which was as stiff as any aluminum crank I have ridden, is available in at least three lengths: 170, 172.5 and 175mm; my test bikes were equipped with 172.5s.

      Karl: I’d love to find a steel bike that actually rides better than these bikes. On most days, I’d prefer these bikes to steel.

  12. Josh Kadis

    From Road Bike Action in April 2009 (

    “Last year Tom Boonen was the only rider on a custom Roubaix SL2. This year Stijn Devolder and Fabian Cancellara had one as well. All of the Roubaix’s unique frame features are in place, including the shock absorbing Zertz inserts, longer chain stays and wheelbase, increased fork rake and more relaxed head tube angle. All this is mated to what is essentially a Tarmac SL2 front triangle.”

    Sounds like it keeps the Roubaix’s geometry but adds the Tarmac’s stiffness.

    1. Author

      Josh: I believe a little something was lost in translation. I want to be careful here because I do a lot of work for RBA and have a lot of respect for the folks at Hi-Torque. I reported quite extensively a few years ago when Boonen first moved to his Tarmac and Roubaix from Time. I did a few different posts for BKW on this. What made Boonen’s bike different wasn’t that it was a stock Tarmac front end, but rather the frame was essentially a 61 with the head tube length of a 58. What I haven’t found out is if for the Roubaix SL2 Specialized did some additional machining on the existing mold they created for Boonen or they cut a new mold. The larger lower HS bearing requires a larger diameter head tube at the fork; it is possible they did additional machining to the existing mold. It’s not surprising that Devolder and Cancellara are on the same bike; they have very similar proportions and impressive flexibility. Boonen’s issue with the bike was that the head tube was too long on the 61 and he couldn’t get the bar low enough and the top tube on the 58 was too short, even with the addition of a custom stem (14cm if memory serves). So they made an aluminum bike to his specs and once that fit was confirmed, they cut a mold.

      You can see a post I did about the prototype here.

  13. Everett

    I love bombing decents on my Tarmac SL2. Corners like Boonen on rails.

    Jokes aside, this is what I expected from the review. Roubaix is simply an all day comfort machine as described, where as the Tarmac is pure race. As are all PRO level bikes. A bit overkill for most of the riding public.

    Speaking of decents: My Favorite is down South Grade of Palomar. Padraig, your decending style sounds like mine. I was dropping my friends that day. Push the fun factor high-up, but with a strong sense of self-preservation; since no one is paying me to ride down this mountain.

  14. eric s

    One tiny nitpick on an otherwise wonderfully-written and informative comparison: ‘elfin armor’ means it’s diminutive. ‘Elven armor’ means it’s made by elves. I’d rather get my weight savings from the latter than the former, if you know what I mean.

  15. Henry

    Merckx preferred a fork rake that resulted in a lower trail then what was common at the time. I’d say Merckx knew a thing or two about the classics. If they increased fork rake on the Roubaix it would not be so difficult to turn.

  16. ted

    great article. I ride a spec S works carbon tricross with the all condition 28c tires for road. It is like a roubaix taken farther for comfort. its easily 98% as fast as the roubaix and 95% as fast as the tarmac ( Ive ridden both) and no contest as far as comfort goes. it ONLY depends if you actually race or not, im my opinion. uphill, it ONLY depends on the engine… specialized has so many flavors ( almost too many)

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  19. beepover

    I have both bikes, 2006 Roubaix and 2006 Tarmac. I originally bought the tarmac and this past year bought the roubaix off craiglist. I really perfer the tarmac. It is the quicker turning of the two. The roubaix as designed, lags on the tail end of the bike. If I had it over again, I should have gotten a second tarmac or another Racier bike.

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