2015 Specialized Tarmac DiscFor the new redesigned Specialized Tarmac, the big story isn’t about the disc brakes or a new geometry, it’s about size specific optimization. On the outside, not much has changed except the paint, but what makes this new model worthy of the version 5 moniker is the completely new carbon layup.

In the past, engineers have always developed a 54 or 56 cm size frame, then tweaked that formula to work for the full spectrum of sizes. On the road, this has translated into riders of different sizes having decidedly different ride experiences. For example, smaller riders found that the Tarmac SL4 exhibited understeer through hard cornering, while larger riders often gave the opposite feedback – and wished that the bicycle would feel more responsive.

So one of the major design goals for the new Tarmac was to create a bike that was stiffer and more responsive for larger riders, yet introduced flex for smaller riders, and maintaining agility across the board.

So how did Specialized achieve these lofty objectives?

Specialized 2015 Tarmac S-Works Disc Module Frame

Going forward, each size will have it’s own specific carbon layup to achieve the desired ride characteristics. There will three different headset bearing sizes and fork steer tubes to help dial in steering characteristics, and dedicated seat stays for each frame size, which will allow Specialized to tune rear triangle stiffness for optimized power and handling. For those familiar with the Roubaix SL4, many of these concepts will already sound familiar.

To help determine exactly what those stiffness and handling goals where, Specialized turned to their partners at McLaren. Using F1 inspired technology and techniques, they looked at rider feedback systems, and dynamic testing instrumentation to measure performance in real time.

They used these sensors to determine load at the stem, seatpost, fork, and frame, so they could learn how riders transmitted forces into the frame, onto the road, and from the road , back onto the rider.

2015 Specialized Tarmac S-Works Frameset

Aside from the major charges to the carbon layup, there were no changes made to the geometry. There will be three versions available of the bike, either with discs or rim brakes, but the S-Works model will use a higher grade carbon to shed nearly a quarter pound. The Pro and Expert models will share the same frame. The Comp and Elite bikes will continue to utilize the existing Tarmac SL4 frame.

In addition to the development of new size specific construction, Specialized has also been hard at work developing a new disc model. The frame weighs aprx 80 gm more than it’s rim braking brethren, and utilizes a pretty unique system to keep shifting performance crisp.

While the majority of disc equipped road bikes utilize the 135mm hub standard popularized by mountain bikes, the Big S has instead built its platform around a special 135mm with a cassette that sits further inboard, where it would normally sit on a 130mm hub. This, in conjunction with a custom hanger that pushes the derailleur in an additional 2.5mm, keeps shifting performance on par with the rim brake model.

Roman Kreuziger tinkoff saxo specialized tarmac 2015Photo by Jakob Kristian Sørensen

The last major change is the new internal seat binder, which was first spotted under Roman Kreuziger a few weeks ago. By ditching the seat collar, not only did the frame shed a small amount of weight, but it allows the round 27.2mm seat post to flex slightly for increased comfort.

As with every new bike launched, this one also promises improved vertical compliance, reduced aerodynamic drag, a double digit increase in power transfer, and it’s awesome.

You can learn more at Specialized and stay tuned for more details!


  1. The marketing release only contained “stiff” three times. When buying a frame I prefer to read how stiff it is at least five times in the marketing release to ensure I am getting stiffed.

  2. 9500USD for the disc/Di2 version will easily brake the 10K Euro barrier here in Europe. Smart move in having the non disc mechanichal DA version available. Too bad for that red/withe/black paint tho,I love all black.

  3. oh man. SRAM is late to the disc-party. they sure wish they kept their deadline of april for the improved design road discs…

    no thru axles… interesting statement by Chris D’Alusio “it doesn’t add anything”

    hurray for another big brand offering road disc, albeit with proprietary wheels

  4. Thru axles, while not exactly helpful for quick changes on the Tour, really help maintain/simplify rotor/caliper alignment.
    And no thank you to proprietary rear hub…

  5. Oh cool, SSD (Size Specific Design) just like Orbea did 10 years ago and custom builders have done for decades to give them credit.
    Boo on the no thru axles. I’ll wait until they catch up in design, oh wait that’s never.

  6. So basically, IF you don’t ride a very big or very small size frameset then, disc brakes aside, the bike is pretty much the same as the previous Tarmac SL4 in terms of geometry, carbon (11r) and technology. Nothing stiffer, nothing more compliant – as I doubt the internal seat clamp makes that much of a difference. Therefore if you ride a 54 or 56 the machine is not really that different from the previous model launched 3 years ago. I’d say that is pretty poor R&D for such a big company. I’d like to add that I’m normally a big fan of Spesh and ride their bikes.

  7. It sounds as if they Specialized is generalizing the sizes. They are assuming that somebody who rides a 56 and larger frame is a heavier rider, therefore making the frame more stiff etc. What if your taller and lighter, not necessarily heavier.
    What if you ride a 54,52 or smaller frame and you carry more muscle and are a heavier rider…they stated the smaller frames will have more flex…which you probably do not want, especially on a Tarmac. I’m not sure if I am missing something here.

  8. Agree w/ others. Thumbs down on the proprietary rear cassette hub thing, and big thumbs down for not having thru-axles.

    I don’t care if discs are not approved by the UCI. I’m not competing in the Tour de France or any other UCI professional race.

  9. @ph, no different from any bike design spec by any other company. All manufacturers have to design any frame around a given set of criteria. Size and weight are often correlated but not always.

    Do Trek or Giant offer light, normal, and heavy versions of every frame size? No, they don’t. Nobody other than a custom builder does that. They have to look at the “average” range of riders and build around that info. If you are outside that range, your experience will be less than optimal. Again, this is nothing new for any model from any big builder.

    Size specific layup is nothing new, but is apparently new to Specialized. For guys like me in the middle size and weight range, there’s not much new here. At least they are trying now to make the bikes better for the entire range of sizes instead of the middle. Progress is progress.

  10. @ph. I think your point is very valid. I deliberately ride a smaller size to my “fit size” because I don’t want to be as stretched out as much, but I still want the stiffness. I do not like the assumption that smaller sizes do not need to be as stiff – think Mark Cavenish. A graph on their website explicitly illustrates that the “STEERING RESPONSE” of smaller frames has been reduced. So unless you’re very small or very large this bike may not be as responsive as the previous Tarmac SL4.
    @Chader09. “Size specific layup is nothing new” – very true. Indeed, progress is progress, however there doesn’t seem to be progress for the men in the middle (sizes), which make up most of the market!

  11. BOO!!!!!!

    NO THRU-AXLE ?????

    I sold my CRUX because the disc break & rotor rub was such an alignment problem with wheel removal (no even wheel exchange). Super annoying rotor rub… Ting-ting-ting

    SPECIALIZED don’t blow it this year on the roubaix and crux, do THRU-AXLE!!!!

  12. I almost feel sorry for the Specialized marketing department (wait, is that redundant?). Not a whole lot to hang their hat on here objectively/visually other than an internal seat binder, so they had to invent the “Rider First” narrative and really play up the size specific layup.

    A cynic might question why this was not incorporated until now, but I suppose it could also be viewed as a testament to how good the current Tarmac is? I just hope the bulk of their R&D is going into the next Venge, what with their fancy in house wind tunnel and all. Other than disc road bikes (meh), seems like aero bikes are where the bulk of innovation is going to be going forward. Just saw where even Purito is racing on one!

  13. If it’s engineered for riders first, it’s engineered for mechanics last.
    “There will three different headset bearing sizes and fork steer tubes”
    This sounds like a nightmare.
    Proprietary press fit bottom bracket with plastic bearing cups? Creeeeeeaak city, & you can’t adapt your way out
    Wedge seat collar? Kids be breakin some seatposts; carbon doesn’t enjoy be smashed in one section. Normal seat collars are hard enough on carbon. Has anyone seen a carbon steerer smashed by a Thompson Elite X4 wedge-type steerer clamp stem?
    Ohh, but they stopped making that type of clamp, weird.
    But that’s how crank brothers does their stems front to back, so it should be fiiiiiiine. Oh wait, crank brothers stopped using the wedge. hmm i wonder if they had any problems?
    “Big S has instead built it’s platform around a special 135mm [hub]…in conjunction with a custom hanger that pushes the derailleur in an additional 2.5mm”
    Wow. This sounds just as confusing as 142+, except even worse in application. “My bike shifted fine until I upgraded from the OE Roval wheels.” Now why would anyone do that!?
    If the dealer charges for all the work the customer’s “practically new” $9500 bike needs, it should be a good experience for both the mechanic and the user. For sure.
    If Specialized dealers want to start recording their calls to the warranty department and posting them, i would be fine with that.

  14. As a big specialized fan, I’m not that impressed. First, this seems like they didn’t put that much effort into a new bike design. These are small incremental changes. Everyone was expecting SL5. In fact, I like the SL3,4 designations, it gives some sense about the frame design. They couldn’t call this one SL5 because it’s not new at all. Maybe they will revive it next year?

    Having any proprietary bits like the rear wheel is a nightmare for long term serviceability.

    Thru axles seem to be the future as well when it comes to disc brake bikes. Trek did it on their new bikes…

  15. Integrated wedge seat binder… no seat collar and no periscope… it means the seatpost is now more exposed, the need for a longer seatpost then. I checked the new geometries, now small sizes come with a 350mm seatpost and bigger sizes need a 400mm one. No weight saving there, and less choices aftermarket…

    No mention in the article, but I assume the SL5 improved wide rim compatibility over the SL4? Some Zipp, HED and other wide rims barely fit before

  16. Spesh’s marketing video claims “15-17% increased power transfer” (https://www.youtube.com/watch?v=KKZywmTsVnI#t=1077). If that is the case then why haven’t they provided size specific conventional tortional stiffness data to back it up instead of their new made up “rear triangle stiffness” and “steering responsiveness” metrics. I have a feeling they have changed this because in terms of conventional tortional stiffness it is no better than the old SL4. Spesh themselves used to claim on their website that power transfer is a function of bottom bracket stiffness and tortional stiffness (In fact Giant have been criticising how spesh calculated it http://www.giant-bicycles.com/en-gb/showcase/tcr/#videos but nonetheless they did presented the tortional stiffness data!). Unfortunately, I am very sceptical and await independent testing by Velo (Velo Lab) or Tour Magazine (most thorough and respected bike testing around).

  17. “Is it a coincidence that every person I’ve ever met who’s clamoring for disc brakes on road bikes is fat and slow”

    Ha! Not fat, not slow. But definitely clamoring for disc brakes.

    As far as lack of thru-axles, it’s surprising. I haven’t seen one in person, but the ROUBAIX SL4
    EXPERT ULTEGRA DI2 DISC looks like it has them. I could be wrong, though. Anyone?

  18. Just taking some stabs here:
    1) This is a remade SL4. Even though I ride a 58, I’m not trading my ’12 in for one of these.
    2) Spez hasn’t been afraid to introduce major changes to their stable.
    3) The new Venge hasn’t launched. Perhaps that will be their major TdF splash this year.

    It sounds crazy, but could Spez be phasing out the Tarmac for something “new” and “different” in the next few years, with this bike being a stop-gap?

  19. JP — “Roubaix SL4 Disc” — No it is QR not Thru-Axle… the 2015 Roubaix or CRUX we can only hope will be Thru-Axle

    Wendell — “Tarmac a Stop-Gap” — I really like this idea! Then Venge is awesome, the wind tunnel optimization and disc break addition could allow them to build a Venge as good as the Tarmac but with tons of advantage over it… Thus only having the Venge (race bike) and Roubaix (endurance race bike).

    Come on an THRU-AXLE the Venge, Roubaix and CRUX! 15mm front and 142×12 rear!

    I’m close to pulling the trigger on the Trek disc break bike, but would prefer to ride specialized!

  20. @bc PLEASE leave this forum and go sit someplace safe in bubble wrap!!!! “can’t work on headsets, all 3 sizes, breaking posts, rear spacing concerns”. It’s half way through 2014, all of you that are resisting what’s happening in the real world of cycling and tecnology need to go find a quite place to nap…
    As for the rest us that threw our flip phones in the garbage 15 years ago in order to prepare for the future (iPhone), are throwing downing sh*t loads of many to buy these bikes and drive forward thinking, speed, safety and above all coolness!
    And PS. We’re not using bike shop mechanics to touch our bikes. If you have google and a $150 worth of tools, you can out mechanic 90% of mechanics in the world.

  21. Is the seat tube actually shorter c-t? I am already maxed out with a 400mm post on a size 58 SL4. If the St is 550mm c-t on the SL4, what is it on this new model?

    I agree they need to ditch the Tarmac. I love mine, but I’m so sick of the curved sloping designs, and was hoping they’d get rid of it ofr this model. It’s even worse on the Venge, so ugly. I’d love to see them do something more traditional, with a flat, barely sloping TT. Somewhere between the new Addict and the Evo.

  22. Cant believe I have to sell this junk… Hate to say it, but I would would rather sell Cannondale or Trek.

  23. looks nice but really expensive. And l am fat and slow and Hell Yeah l want Discs and Thru axles!!! l ride for fun and l want what l want…got a problem with that muthaf***ka

  24. ive a 2014 crux an sure thru axles would be nice but the alignment isnt thaaaaaaaaaat bad, i can align it properly then remove/put back the same well without any issue.

    poorly aligned it does indeed hit (ching ching ching… 😉 on remount. but after a few tries i got the hang of it when calibrating the rotor and never had the problem again when switching wheels.

    it MAY touch sometimes in hard corners + rocks + speed + blah. but thats it.

  25. Wow those different size headset bearings must be why I can’t steel my small/large steel 1″ steerer bikes. Steering characteristics have nothing to do with geometry huh.

  26. Awesome, not even 5 months into 2014 and the bike season and I have to discount all my stock because the 2015’s are already being released.

    Fantastic to watch this industry commit suicide.

  27. Hurry up with the S-Works Venge, Expert & Comp Venge Disc equipped models!!
    They’re testing discs on less important Roubaix & Tarmac before letting loose with the REAL DEAL 🙂

  28. Hoping that one can get a regular hanger to run with regular wheels…? Or maybe they’ll make two different free hub bodies? Meh.

  29. @Tyler
    Don’t know about America, but here in Europe almost all Tarmacs (especially S-Works) have been sold out since a few months back and customers are going crazy. So this launch DEFINITELY helps the dealers and the industry, at least here.

  30. Why people are in such a hurry for disk brakes ?? I’ll keep my road bike simple stupid and not a cyclocross lookalike machine. Back in my place I barely use brakes anyway.

  31. I say good on Spec for finally realizing that a 58 cm needs different layup than a 52 cm. Disc brakes are an obvious change — only UCI-licensed Luddites don’t want discs. I already own two bikes with disc brakes and will never, ever, go back. Boo on non-standard hubs, but hooray for at least caring about the fact that chain line is so hit-or-miss with 10 & 11-speed groups with 135 spacing. Why is it ok that Ultegra now has _two_ crossover cogs in the small chainring? I blame Shimano for this!

    Gotta just shake my head at the prices of these bikes. Before I got (somewhat) “slow and fat”, I could never afford a bike in this price category. Now that I can, I say “wait a minute, I could build a custom bike for the same price”. Any good custom builder says, “OK, you’re 6′-2″ and 165 lbs? Fine, what kind of ride feel do you want?”

  32. Well, on the plus side, now maybe different sizes will ride differently as they should.
    But… 3 different headset bearing sizes?? Really??
    And disc brakes on your racing bike before they’re UCI legal??
    More proprietary hub spacing standards??

    I get it – make what people will pay for. But none of this is exciting, or innovative, or relevant.. just arbitrary design changes to say “look at me!”

  33. @Alex – I am no engineer, but I would assume that understeer is very minimally impacted by stiffness and much more dramatically impacted by geometry.

  34. @rub-a-dub

    Ask yourself about Specialized as a supplier in that case; they didn’t adequately prepare for your market demand, now are forcing rush production of 2015’s in the middle of the summer, which means sure, you have some new Tarmacs to sell, but at what cost to any 2014 models left in your store?

    Retailers have a hard enough time getting anyone to buy without a sale; now Specialized is helping to continue setting a precedent among consumers to wait past spring and buy mid summer when all the brand new 2014’s are on sale, making their way for 2015’s.

  35. Some nice refinements. I pretty impressed with the level of detail here, particularly from an R&D perspective. I’m not sure custom frame builders have the same tools or technology at their disposal. The partnership with Maclaren F1 will no doubt bring another level of R&D to the table.

    I love my SL4 and the new bike looks super clean. Not sure thru axles are necessary on this type of road bike. I’ve never had issues with QR’s coming loose. Not convinced about the proprietry disc hub though but can see the benefits in shifting performance.

    Black and White one for me.

  36. my appreciation of trek has only grown after dealing with them and spesh at the same time. not perfect but MUCH better in comparison.

  37. @ph and @AA watch the 30 minute video that is posted. They discuss the differences in height and weight etc. in developing the frames… @AA you’re assuming too much and are jumping to conclusions. They clearly stated increased compliance among other things for even a size 56 and your smaller bike is going to be no noodle. Do your homework rather than bash specialized with no knowledge of what you’re talking about.

  38. Disc brakes cause SERIOUS drag, something that can just be designed away. It’s probably on a par with the drag you save by going with mid-deep wheels. It also adds weight.
    You people REALLY want to put that on the Venge, of all bikes? The idea is just silly.
    “Oh, I want an aero bike and am willing to accept the minor compromises like ride quality and slightly less torsional stiffness to get lower drag. But please, give me discs so I can jack the drag back up to what it would be on a Tarmac.”
    For anyone not riding mountains, and doing it on carbon clinchers, it’s a solution in search of a problem, and an expensive solution at that.

    Then there is the safety issue. This isn’t just UCI being like UÇI was before it’s new leadership. Massive wrecks aren’t unusual in my races and are already dangerous enough without havibg to fly into a whole nest of what essentially are deli meat slicers.

  39. Oh noes!!! Red hot spinning discs of death!!! Retro grouches are going to HATE that. I love all the comments about danger of discs in racing. Never mind the giant chainrings with sharp teeth all over them… or those pointy cables… or all the splintering carbon that could happen with all the super light wonder bikes. I swear people hate advancement, no matter if it’s a step in the right direction or not. All the euros shunned disc brakes on mountain bikes for a long time as well. IMO Evolution is a good thing.

    The only thing I REALLY don’t like about this bike is the funked up hub spacing. Just make it work with a normal 135mm hub. Most people will NOT be running roval wheels.

  40. Keep ’em coming guys….it’s you the reader who REALLY knows what’s up, because you read other things on the internet.

  41. @Greg… I’ve been a professional bike bike mechanic for 20 years and BC is right on. The wedge clamp is not a good idea. Same with the proprietary hub and the BB interface. The size-specific sales pitch is just that… a sales pitch that’s been around for a very long time. Why weren’t they concentrating on the riders last year? Or 10 years ago? Serotta started working with Specialized on BG Fit a VERY long time ago.

    I’m not saying that this is a bad bike, but there are a few “innovations” being highlighted here that I wouldn’t purchase. For this kind of money you can find bikes that are better designed.

  42. There are some initial ride reviews from other journalists out there on this new Tarmac, both the rim brake and disc brake versions. Granted, there’s probably no way in hell those people with actual experience on the bike can know more than the deeply knowledgeable and intellectual crowd that has so far offered their choice insights above, but those reviews might be worth reading to those who aren’t afflicted with a knee-jerk thought process and who actually know how to critically think.

  43. I’m in agreement with no discs really necessary unless you’re stopping frequently in the wet. I can’t imagine that any good could come of them in crits, for example. I love them on my ‘cross commuter, but I live on the rainy west coast. They’re super safe in the rain. The rim brakes, on the other hand, make for a much more compliant front end, and work fine in the dry (and reliably in the wet if maintained). Most of my road rides are in decent weather, and on relatively flat terrain. Discs are overkill in that regard. For someone who’s riding in the wet or downhill frequently, the discs are significantly better.

  44. @ Hawtie. By the 30 min video, do you mean the 27.50 min video for which I provided a link in my post from 05/10/14 – 2:01pm? If this is video you refer to, then maybe you’ve misunderstood me or I haven’t been clear.

    While “every 10 percent you raised a rider’s center of gravity, you increased loads by 18 percent” maybe correct. Just because you ride a smaller frame doesn’t mean you are as light as the pros. Noodle or not, a graph on their website illustrates that the “STEERING RESPONSE” of smaller frames has been reduced when compared to the SL4 because of feedback from the likes of Alberto Contador. It maybe right for Alberto but how many of us are actually as light as pro cyclists?

    My point is that lab bike testing is actually pretty scientific. Normally Specialized reports a standard verifiable metric. However this time they choose not to provide overall size specific tortional stiffness data. Why? I think it is health to be sceptical of all marketing claims, irrespective of the company. Companies are biased, they make claims and questioning them is not tantamount to “bashing”. Verifying the truth requires more objective third party analysis by the likes of VeloLab and the German Tour Magazine/international etc. Time will tell, I am happy to be proven wrong with facts but not shouted down.

  45. while I’m always excited by what is coming new from the big red S…..I almost feel a bit undersurprised by this….even a bit disappointed….
    1. disc on a road bike….MEHHHH..Honestly its something that just seems like overkill
    2. Rider first engineering: MEHHHH…BEEN THERE DONE THAT. Not from specialized but its just not that exciting. But maybe riding this new concept may be the convincer….
    3. hidden seat binder….MEHHHH…clean looking but mixed feelings…just not something that gets one excited…..
    I feel that the Tarmac is a ripper of a bike (ive owned several over the years) and due for a facelift of sorts…and this is all they could come up with. Where’s the new innovative sh-t?
    does not make me dislike them at all, just a wee bit uninspired….

  46. There are two main reasons why I would buy a new bike:

    1. New innovations/technology compared to previous models
    2. New and refreshed facelift

    This “new” tarmac really doesn’t have either of the above criteria IMO. Having said that, I still think it’s a great bike. Something I would definitely pick up if I didn’t already own an SL4. But for now, I will hold on to my SWSL4 and hoping the new Venge will be more exciting.

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