When the S-Works SL6 Tarmac was launched last year, it introduced a few new design innovations Specialized had been developing for the previous six years. The result was a lightweight bike with crisp handling, advanced aerodynamics, and ride compliance tuned for each frame size. As nice as that bike is, the version we all knew would eventually arrive is finally here in the S-Works Tarmac Disc.

The 2018 Specialized Tarmac Disc is the latest bike in the S-works lineup.

The newest edition of the Tarmac line wasn’t just refitted to wear hydraulic stoppers. Integrating the disc system required an extensive revamp of the frame with an extra 200 individual pieces of carbon added to the layup. While the geometry and tube shapes were mostly retained, the internals of the frame were radically altered as to not sacrifice weight or aerodynamics. According to Specialized’s Win Tunnel expert, Chris Yu, the new Tarmac Disc is as sleek as the first generation Venge.

The 2018 Specialized Tarmac Disc is the latest bike in the S-works lineup.

At 800 grams for a size 56cm in the lightest paint scheme, the disc model weighs no more than the rim brake frame. The fork on both models is slightly heavier than some might expect at 338 grams but was designed to offer the optimal ride qualities rather than low gram count. The fork plays a major role in defining the Tarmac’s overall ride feel with rigidity a primary design objective. As explained by Chris Yu, “The stiffness of the fork contributes to the Tarmac’s precise race-inspired handling and improves rider confidence during hard cornering and braking.”

The 2018 Specialized S-Works Tarmac Disc brake road bike also gets their new power meter crankset

As a complete bike, the Tarmac Disc weighs just 14.65 pounds putting it just below the UCI legal limit. The addition of the disc brakes does add a modest amount of extra weight over the rim brake model which is .65 pounds lighter for the same size 56cm frame. The extra weight is distributed evenly throughout the bike with reinforcements to the rims and hubs. A few extra grams are attributed to the one major standout feature of the new bike, the much anticipated S-Works Carbon Power Cranks. More on those later.

The 2018 Specialized Tarmac Disc is the latest bike in the S-works lineup.

Like the rim brake bike, the new Tarmac was designed with geometry data gathered by the fit experts at Retul. Both versions are identical with regard to frame metrics and sizing, save for one minor difference. Whereas the rim bike has a chainstay length of 405mm or 410mm depending on frame size, all disc bikes have 410mm stays. Complete bikes are available in men’s and women’s models, both using identical frames – only the bars, cranks, and saddles are gender-specific. There are six men’s sizes (49, 52, 54, 56, 58, 61) and five for women (44, 49, 52, 54, 56).

2018 specialized tarmac disc s-works frameset

To maintain the optimal ride attributes initially achieved with the Tarmac Rim, the disc frame was also designed to incorporate Specialized’s Rider-First Engineered philosophy. Each frame size is not only built with a specific geometry, but tube shapes and layups also vary per size. A Tarmac Disc frame consists of more than 500 individual carbon “plies,” each placed where it is needed most based on size. One essential element to the plush road feel is attributed to the new D-shaped seatpost. The upper 100mm of the layup was tuned for increased rearward compliance.

The 2018 Specialized Tarmac Disc is the latest bike in the S-works lineup.

In keeping with tire trends, the new frame was shaped to accommodate up to a 30mm tire, although complete bikes will ship with 26mm Turbo Cotton tires fitted to CLX 50 carbon disc rims. Aerodynamics at the front wheel is improved with a Flush Axle System which eliminates the lever. The included and optional 6mm, 12×100 flush bolt also drops the weight by 30 grams over the standard RWS lever. Standard 12×142 rear axle spacing leaves ample options open for aftermarket wheels.

Available now, the S-Works Tarmac Disc sells for $11,000 for the complete bike built with Shimano Dura-Ace Di2. That includes the all-new S-Works Carbon Power Cranks and carbon aero wheels. Framesets sell for $4,500 to $5,000 and include CeramicSpeed BB30 bearings, headset, seatpost, seat clamp, and necessary cable routing accessories.



      • Yes. The difference in MSRP frameset cost. S-works Tarmac Pro Disc ~$4.9K USD; Giant Propel Advance SL 0 ~$2.9K – 3.2K USD depending on source. Which means that the top-line Giant you are referring to has an additional ‘value’* of ~1.5 – 2K in components.

        Would it help to draw a pie-chart?

        *value here is hard to measure due to the in-house production of wheels, cockpit, etc. where there has been few specific comparisons between those branded products.

        • Propel is equivalent to the Venge.
          TCR is closer the Tarmac.

          Top of the line is still 10k bikes, there is no value here.

          • TCR MSRP Frameset is $2.6K USD, leaving 2.3K of ‘value’ missing between the two and getting closer to my original estimate of 200%.

            Thanks for proving the point Smale Rider.

            Ryan – not considering buying either? Then why are you here?

            • Value is completely subjective… A Propel frame might cost less but it still says “Giant” on it and not S Works… See what I did there?

              Also because the look similar, doesn’t mean they perform similarly… The new Tarmac frame is like 740g and stiffer than a Giant.

        • Who cares? If people don’t feel its worth it, the market will speak. Thankfully the consumer has a wide range of very good options at many price points.

    • Furthermore, the Tarmac isn’t Specialized’s aero bike, so the Giant it competes against is the TCR Advanced SL Disc… I mean come on, I don’t like Specialized either, but if you’re going to diss them, at least know your stuff! 🙂

    • So you think the wheels stem and handlebars are worth $1500-2000 more? Framesets are not always a good deal from Spec but the completes (that most people buy) are pretty equal. Buy the way, the pie chart comment was condescending. I was perfectly polite in my comment and didn’t understand that you were comparing frame sets. We don’t HAVE to be rude in comment sections, OK?

      • In my country, there is a saying which translates roughly to ‘perception indicates thought’ which is likely why, if you had made the pie chart comment, it would have been condescending. Whereas I think it would actually be helpful, particularly with the following:

        Price of complete bike is some function of frameset cost + everything else; since ‘everything else’ includes common groupsets, those can be taken out of the equation. what is left for accounting of price is proprietary components + frameset. Since we have previously established what the respective frameset costs are, relatively, the remainder is then proprietary components. Which means that for the *same amount of money* you are paying less for a frameset and more for proprietary components for the quoted Giant. Since it is generally understood that cost is some function of manufacturing capital, materials, labour, shipping, markup, etc. and that higher cost is often a result of the greater capital and material inputs required to achieve certain performance characteristics, it can be generally said that higher cost reflects higher quality/refinement in the mfg process. As such, would it not follow the above dissection of price (which would be helped by a pie chart) that there is some function of higher quality/refinement in the giant components due to the lower frameset cost?

        Blah blah blah – I thought this was a widely understood concept. It’s basic algebra to remove commonalities from equations. My mistake.

        SAWTOOTH – I haven’t read any reviews to the ride characteristics or testing results. do you have any you could share?

        JBikes – that is exactly what I said in my first comment.

        Corey – That isn’t the point. It isn’t about manufacturer defined categories, but rather frame characteristics, which sees more similarities (right down to the differential CF layup) between this machine and the Giant Propel Advanced.

        • Man, a bike isn’t a commodity nor is it priced like one. You are dissecting prices that are priced in any real way that correlates to production cost. Big S may, through its research, realize it can meet production-demand balance at $4k msrp for whatever reason. If they miss, they will go on sale or prices will be lower next production run.

          A person may pay significantly more for looks, perceived quality, fit, bike shop access, etc. If it was simply pie-charting your way through bikes to establish “value” like some kind of robotic actuary we’d probably all be riding Fuji’s, GT’s or Jamis’ (all very nice bikes btw).

  1. Might have to rethink the quantity of advertisements you guys are adding to content. On my iPhone I’ve got 9 ads and 6, 7 if you count the top banner pic, pics in the article.

    • I don’t know why people ask this question any more. First of all, it explicitly says in the article what the claimed tire clearance is. Second, those Conti’s you call out usually measure way bigger than 28mm wide depending on the wheel. So its up to you to either research how wide the stays and fork are (hint: Cycling Tips has actual measurements of the frame in their review) or get a shop to test fit the specific wheels and tires on this specific bike for you.

      Or I guess you can come on here and whine about not getting enough info for your super specific question, even though we can all see the article is clearly just a reprint of all the marketing material and not a real review.

    • Honestly, I’d prefer all my future carbon frames to be machine made. Humans make mistakes, regardless of the country in which they do their work, or are push to a pace in which mistakes will happen regardless of care taken. Never understood the desire for “handmade” in mass produced goods.

      • And Im not saying this Spec is machine made. Its handmade as well. I think BMC is a main driver of automated machine cfrp frame manufacturing, but I am not sure if they are still doing this.

        • BMC don’t produce anymore it automated frame. Was a failure. BMC frame are manufac in Asia.
          Time rtm tech is probably the most automated actually because tubes (in fact whole triangles now) are woven by the rtm machine.

    • I get what you are implying.
      In my mind, when a manufacture says a frame fits up to a 30mm tire, they should be clearly stating that per CPSC/ISO clearance standards, the actual max width of the installed tire in the bike frame is “X”mm wide regardless of what the stated size is on the tire, since tire manufacturers obviously don’t hold to consistent specs across brands. So if a 28mm conti measures 32mm, you as a consumer know the frame manufacturer doesn’t condone that, but if a 30mm michelin measures 28 on your rim, you are in the clear.

    • I have these same wheels on my Roubaix and a size 28 Spesh tire measures out to over 30. Frankly you want to set these up tubeless so forget the Conti’s. I run mine at 70 PSI and it is nice…

  2. Is Specialized going to sue all of us for talking bad about them?!?!?! Has anyone receive a cease-and-desist yet?!?!?!?! Wait, is that a lawyer outside my door?!?!?!?! Did you hear the one about the Specialized lawyer, a rabbi, and a priest?!?!?!?!?!?

    Guys, am I right or what?! C’mon, give me a high-five, don’t leave me hangin’! That was funny, right?!

  3. The real tragedy on this bike is the fully built paint job options. Congrats on making a good looking bike tough to keep an eye on.

    In regards to the drag claims, I’m sure that through most of the yaw range its rather close. Only some rare instances would the drag be higher in high yaw situation and you’d be too pissed off about the wind to care anyway. Same with the weight differential, to small to make anyone besides the weight anal to care.

    Besides the braking aspect itself, I get the advantage of discs at the rear of the bike. Seat stays have no longer to contend with brakes and can be molded for better compliance. Through axles and the additional carbon to an already asymmetric area of the bike should make the rear even stiffer right where you need it. Its the front of these bikes that have me wondering. Rim at the front allow symmetrical design fork, hub, and wheel. The mount for rim brakes are well located in terms that the crown was already a reinforced part of the fork. You still need the fork crown being robust but now the bottom end of that fork has to be stiffer, with a possible loss of compliance to the rim version.

    In a recent review of the BMC TM SLR01, a number of riders commented on preference to the rim brake version in terms of steering. BMC admitted its DB fork was a little off in pure numbers as compared to the rim fork. They preferred the DB version cable system due to no cable resistance through its range of motion, so it had some wins of its own outside of sheer braking. I would be curios to see responses from reviewers who could ride the two S-Works bike back to back. It seems that some compromise is being made at the front for these braking gains. Even the truth of this question is mostly inquisitive as either posses a very high degree of capability.

  4. Pretty easy to build a bike that does everything this does and weighs the same for far less, and you wouldn’t have to show up the the local 5 miles rich guy coffee ride with the exact same bike as everyone else.

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