The Specialized S-Works Tarmac SL4, Part I


I’m going to start this post in a way that you’re not supposed to start a review—on a sour note. I didn’t see the need for this bike. Initially, it struck me as the inevitable result of the Specialized product machine. The template was struck some years back following the introduction of the Roubaix. The company alternates between a new Tarmac and a new Roubaix each year. In odd-numbered years Specialized introduces a new Tarmac, while there’s a new Roubaix in even-numbered years. Fall of 2011 required a new Tarmac.

When I first rode the Tarmac SL, I was not particularly enamored of the bike. I was a bigger fan of the Roubaix. I still think the Roubaix is the better bike for most non-racing riders. The issue for me was that I was accustomed to grand touring bikes; the two bikes I’d spent most of my miles on prior to first riding a Tarmac had relatively low bottom brackets and longish wheelbases. The Tarmac was a big change; the Roubaix less so.

It wasn’t until I began reviewing the Tarmac SL and the Roubaix SL back to back that I really acquired a taste for the Tarmac’s handling. I’d ridden plenty of bikes with handling as sharp as the Tarmac, and had disliked plenty of bikes with such quick handling. Well, “dislike” might be a bit harsh; they wouldn’t have been my first choice. The Tarmac showed me that with adequate stiffness (particularly in the fork and at the head tube) sharp handling needn’t make you nervous. By the end of the review I’d come to the conclusion I actually liked the Tarmac better in my favorite terrain—the canyon roads above Malibu. Here’s the post where I changed my tune.

Next, Specialized came out with the Tarmac SL2. I didn’t like that bike. It was okay on smooth roads, but anything rougher than a chick flick would rattle you like a paint shaker. It made chip-and-seal feel like the Arenberg Forest. That said, I know plenty of people who liked that bike.

Two years later Specialized came out with the S-Works Tarmac SL3. The biggest difference between those two bikes was in the rear end. The seatstays were flattened and reduced in diameter. And while I was told there were some changes in the layup of that frame, the folks I talked to didn’t go into too much detail. Broadly speaking, I was told that the layup was changed to permit more flex vertically while keeping the bike as rigid as possible torsionally.


So here’s where I have to address that trope of “vertically compliant but torsionally stiff.” It’s become a joke because some of the publications out there use it as a crutch to convince you that a Toyota Camry is a BMW M3. There’s nothing wrong with a Camry, but very few autos can provide the performance of an M3. That line about “vertically compliant but torsionally stiff” rings hollow because at a certain point, if all bikes have that quality, then it ceases to be a way to distinguish bikes. And we know they aren’t all that way. There are real differences.

When I say I liked the SL3, I mean I loved that bike. Here’s that review: part 1 and part 2. It was one of my two or three favorite bikes I’ve ever ridden due to its particular constellation of road feel, performance, handling and weight. It didn’t need improving. When you’re putting out one of the best bikes on the market there’s a risk in trying to improve upon your work; there’s a real chance that no one will notice the difference. And the risk there is that if consumers can’t tell the difference between the old product and the new, improved one, they will begin to think what you’re selling is smoke and mirrors.

After assembling the S-Works Tarmac SL4 (and I’ll come back to the assembly in a bit), I went for a ride on the SL3. It was a short ride in my neighborhood, less than two miles. Then I jumped on the SL4, and did the same circuit again. I took care to make sure the tires were pumped up to the same pressure. The difference was not night-and-day, but the bikes were unmistakably different.


Product Development
It’s common for fans of handmade steel and titanium bicycles to deride carbon fiber bikes for lacking personality, or sometimes it’s phrased as soul. When you’ve got a one-man shop, the marketing effort is pretty obvious. Land Shark begins and ends at John Slawta. As it should. But with a bike like the Tarmac, there’s quite a team involved and it’s not exactly possible to market a bike around every engineer and layup craftsperson who worked on the bike. And believe me, if you’ve ever seen someone doing layup, you begin understand that it really is a craft, just like brazing or welding.

The team responsible for the Tarmac includes some of the most knowledgeable people within their respective fields that I’ve met in the bike industry. And the resources that Specialized put into the bike are staggering. I was surprised to learn that each iteration of the Tarmac, from the original SL up to the current SL4, received its own set of molds. That’s a new set of molds every two years. That’s a lot of tooling. Consider that some Italian bike companies are still using the same frame shapes from six years ago.

So why new molds every two years? Easy. With each iteration of the Tarmac, Specialized has altered the frame shapes, slimming seatstays here, swelling the down tube and growing the bottom bracket there. Like other carbon fiber frames, the Tarmac is made from several monocoque sections that are joined after molding. With each new iteration, the locations of some of these joints have shifted based on what the engineering team has learned about the previous bike.

In talking with members of Specialized’s engineering team, they revealed that feedback from riders on the HTC-Highroad team indicated they needed to increase vertical compliance without sacrificing overall torsional stiffness. While riders said they liked the S-Works Tarmac SL3, the front end was a bit harsh for a 200k day. To that end, Specialized replaced the 1 1/2-inch lower headset bearing with a 1 3/8-inch bearing and decreased the diameter of both the fork steerer and the head tube. Another important evolution in the Tarmac is the move to Specialized’s OSBB design, which is essentially a press-fit 30. Such a large bottom bracket structure—and similar ones by other manufacturers—has eliminated bottom bracket flex that I once used to take as a given in all bikes.


Aside from the desire for a more gentle front end, one of the few criticisms sponsored pros had for the S-Works Tarmac SL3 was that the rear brake bridge wasn’t stiff enough, that the rear brake would chatter and squeal. To correct that, the brake bridge was beefed up and right at the brake bridge the seatstays were also beefed up.

I could tell you that the bike uses Specialized’s FACT IS 11r carbon—okay, I have told you that it has the FACT IS 11r carbon. But that didn’t help, did it? Information ought to answer questions, not raise them and while all that stuff signifies that the carbon fiber material and layup that Specialized is using is more sophisticated than anything they used in the past, it really doesn’t tell the consumer anything objective. Not a crime, but not nearly as helpful as they’d like us to think. The upshot—the part that matters—is that the S-Works Tarmac SL4 is the lightest frame Specialized has ever produced, that is, with the exception of the women’s Amira frame. My 58cm frame weighed in at 898 grams and likely came in a few grams heavier than the matte carbon version due to the number of coats of paint necessary to generate that bright arterial red.

Up next: the build, the ride, the bottom line.

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  1. Brian

    I was close to pulling the trigger on the SL4. I opted for Giant TCR Advanced SL. So far happy with the decision. I look forward to your take on the ride quality of it.

  2. thrash

    Any idea of what the fork recall on the SL4 is about. Word for corporate is vague.

    I have had the S-Works 2, 3 and 4 and agree with you completely. While not many bikes descend as well on the PV Coast’s fast sweepers as my old Serotta the SL4 is VERY stable at high speed. This is in the close quarters 50MPH range where stability means everything.

    1. Author

      Thrash: I haven’t heard any details on the nature of the recall other than they have some concerns about the fork steerer. I’ve not seen any reports of actual failures, so it doesn’t sound like anyone riding a Tarmac SL4 is in imminent danger of hitting the deck due to a broken fork. That said, I’ve asked my contacts in Morgan Hill to see if they are willing to reveal anything more. If I hear something, I’ll make sure to pass along the info here.

    2. Author

      All: Regarding the recall, according to the CPSC release, there have been two incidents involving the fork; in one, there was a fall that resulted in facial lacerations requiring stitches.

  3. Alex TC

    Thanks for the review Padraig, I was looking for something like this and this series came in good time. As always, it´s good to read your bike and equipment reviews.

    I love my SL3, use it for ride/train/travel/race since 2010. It´s one of the best bikes I´ve ever threw a leg over, and that´s no small feat since I worked as tech editor for a local big bike mag untill 2003 and tested/owned lots of bikes during those yrs.

    I remember it being a sensible, marked upgrade in ride quality from my old SL2. Something I missed, or didn´t notice, coming from the SL3 to the SL4 that I had the chance to test for a couple of weeks when it came out, and again with a new Sram RED groupset and new Roval wheels in 2012.

    IMHO it´s a slightly more refined, marginally lighter and subtly more comfortable ride compared to the SL3, I admit (or maybe it was just brand new compared to my 2-yr-old steed). But as I rationalized, I can always shave a few grams here, pump 5psi less there, achieving almost the exact same result and save a LOT of money. Of course, a new bike is always a new bike and nothing compares to THAT feeling.

    Currently the only bike that tickls my fancy and is giving me second thoughts to move away from my SL3 is the Cannnodale EVO. Tried one late last year assembled with the new RED too and a light (but not superlight) kit, and it proved much, much lighter, more comfortable (and at the same time rigid) bike than my SL3. I noticed a no small gap in performance, overall.

    I´ve been on S-Works Tarmacs for the last 5 or 6 years. I totally understand someone going for it as the first race bike, as I once saw the SL, SL2 and now the SL3. It´s one mean beast. right there with the best. But coming from an SL3, it didn´t make me want to change. I now see myself moving to another brand and model, or maybe waiting for the SL5 if I can keep my consumist self under control for that long.

  4. Wsquared

    From the article in VN that I posted a link to above:

    “Specialized Bicycles has announced a voluntary recall of the front forks on all models of its 2012 Tarmac SL4, 2013 Tarmac SL4, 2013 Crux, and 2013 Secteur Disc bikes and framesets. The recall was initiated by Specialized after learning of an issue with the forks’ carbon fiber steerer tubes on these models that, in a small number of instances, can crack or break. The recall is projected to affect approximately 12,200 bikes in the U.S.”

  5. marks

    Must say I do not like the red paint. Didn’t like it at the Olympics much, and would be embarrassed to ride one at home. Would have have to get a Quick-Step version. I ride an old S-works Tarmac that I have loved since 2006 and am looking at saving up for the SL4.

    Padrig – is it true the Firecrest 303s are not rated for this bike (too wide, I heard)? And what version of DA did you build this with? Is the DA 9000 compatible with the S-Works cranks and rings or do you have to go the adapter route and use a DA crank? Given those are carbon cranks, could you integrate a Stages power monitor anyway, or would it unbalance the bike?

    1. Author

      Marks: It’s true that Specialized says not to put Zipp 303s on the Tarmac SL4 because the rims are too wide given the thickness of the chainstays. I do know a rider who tried it anyway and was happy with the result. The bike I received is as shown, with 7900 Dura-Ace. The Roubaix that I have seen with 9000 were all spec’d with Specialized’s crank, not the new D/A 9000 model. The Stages power meter is so light you don’t have to worry about creating an imbalance.

      Anthony F: Sharp eye. I’m on the bubble between Specialized’s 56 and 58. I’ve ridden both over the years and as a result of the fitting that I went through earlier this week, I think I might be going back to the 56 next time. I’m not as easy to fit as I once thought. I’ve got a really long inseam, shortish torso and big wingspan. I’ll address that more in part two.

  6. rarrar

    I ride a SL2 and love it even if there is noticeable road chatter. But this is after riding two years on an Allez. With the same geometry, handling and bb stiffness are the two most notable differences between the two. But Specialized will improve the frame based on their premium frame competitors not just road bikes in general. And i assume many customers are more inclined to go towards comfortable bikes being those customers are older (and have more spending power).

  7. Mike

    Not a fan of the colourway. Or paintjob for the non-hipsters. I much preferred the more subdued and simple S-Works of old. Red to black transition seatpost? UGH! Pick a line width and pattern, and stick with it. And there’s red lettering on white, white lettering on red, black lettering on white, white lettering on black. (And I didn’t even get to the wheels). And to top it off (because apparently it needs more visual lines), World Champion stripes?! Guys, dial it back like 3 notches.

  8. John

    I believe that one of the two failures that occurred with the forks happened on my local team/weekly ride. I didn’t happen to be with the group when it happened so didn’t see it, but the stories that were told were one of a nasty crash. This guy went right onto the deck and it was not a minor accident in any sense. I have just purchased a new Tarmac about a week before the recall and it immediately went to the shop to have the fork inspected. I think that Specialized did the right thing by coming clean and recalling the fork immediately. It sounds as if they identified the manufacturing issue and know what to look for in the returned forks. I would recommend that if you have one of the affected models you get to your local shop ASAP.

  9. Martin

    Hi Padraig; what bottle cages are those? I have the exact same bike and am looking to find ones that go with the busy colour scheme – they look spot on. P.S. I love the bright red, but I suspect I’ll be going for black bar tape when the white dirties up. Also thinking about removing the stickers from the wheels…..

    And finally, I’ve already sent my fork back for a check. Very painless, all ok, and made even better by the £100 voucher it came back with!!

  10. Dale

    I ride an S-works SL3 and love it. I don’t want a new frame for the first time I can remember after biking for 30 years. I just put on a 2013 quarq, 2013 404 tubs, 2013 red and full ritchey carbon cockpit. Now I just want to paint the frame solid white and lose the saxo stripes. That is my only gripe, the stripes..

  11. Jonathan Dubel

    Purchased an s-works sl4 red about a month ago and love it!! Having raced Italian steel 30 years ago and them a brief stint on Italian aluminum 15 years ago I am blown away with how far bikes have come!! Mine is all black with black carbon rovals and white and red ghost decals. Very steath and sinister. I also agree that the same bike in some of those over the top color patterns would completley repulse me. I dont know who at Specialized dreams up some of those color combinations???

    Now I just need a year or so and about 10,000 hard miles in my legs to do this fine ride justice.

  12. earl

    Hi, I have the same s works sl4 – amazing bike! I’m fitting a new headset and wondered about greasing the cup/headtube interface? Is this to be left dry as the contact is metal to carbon? It would seem to make sense to grease the metal race on the forks to prevent water ingress, but not sure about the rest and wondered what you did?

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