Test Lab: Specialized Tarmac SL4 Expert

There are few bikes in recent memory that have been as prevalent in the WorldTour as Specialized. By virtue of multiple team sponsorships, the big S can be seen gracing head tubes in almost every in-action shot from any Grand Tour in the past few years. If you factor in Specialized helmets, and Specialized shoes, which are worn by some of the teams which do not use Specialized bikes, it’s clear to see that Specialized has some major stock in the game. The names really tell the story: Cavendish, Boonen, Martin, Contador, The Schlecks, Vinokourov, Cancellara, Voight and Goss. All these guys have plied their trade on Specialized bikes, and more specifically on their Tarmac models.

The Tarmac line of bikes is described by Specialized as their ‘pedigree race bike’. It’s a light and stiff carbon machine that is built for pro level Grand Tour racing. As one of the big three (along with Trek and Giant), Specialized offer a mind-boggling range of models. For riders that want a bike tailored to their specific riding style it seems only appropriate that a brand that calls itself Specialized would deliver not one, but three different lines of performance road bikes.

The Tarmac line of bikes debuted with a carbon/alloy frame. At the time this was cutting edge, but seems so primitive in hindsight. All Tarmac models are now made from carbon, even down to the base model. The original Tarmac was superseded by the all-carbon Tarmac SL, then SL2, SL3, and now the latest SL4. The SL4 is a new frame shape that has been refined from the SL3 shape and as always, it’s a case of lighter and stiffer. The SL3 shape is still featured on the base level Tarmac bikes and SL4 frames start at the Expert (on test here) and run through to the Pro issue S-Works level.

Specialized really push that the Expert frame is a premium product in its own right. Their own testing compares the new SL4 and SL4 S-Works frames with the superseded SL3 S-Works frame as well as premium frames from the likes of Trek, Cannondale and Pinarello. Performance metrics of bottom bracket stiffness and torsional stiffness are measured, as well as stiffness relative to weight. In torsional stiffness the SL4 Expert frame outperforms the previous SL3 S-Works model, and is only a fraction behind it in bottom bracket stiffness and carries just a 100g weight penalty.

The Expert was a great chance to ride a frame that is contemporary and almost indistinguishable from a top tier product, but hung with everyman parts at a price that many can afford. At $4,000 (or $3,999 to be exact) a non-cyclist will surely baulk, but $4,000 for a cutting edge frame with bankable parts seems like a reasonable deal to those of us hopelessly fighting the cycling gear virus. If you consider that the SL3 S-Works frame on its own (a grand Tour winner no less) carried a price tag equal to that of the complete Expert bike, the Expert seems like it should offer amazing bang for the buck for the self-funded racer. The current SL4 S-Works frame bests the Expert in all metrics measured, but at $4,000 for the frame you are again faced with the question of how many dollars are you willing to part with for fractional performance improvements, especially when the level of performance available so closely mimics that of the pro level.

Specialized have often used the term ‘innovate or die’ in their marketing, so each new product generation is faced with some heady internally-generated pressure. Minor tube shaping and carbon layup tweaks have resulted in the SL4 frame being lighter and torsionally stiffer than the previous SL3, but these physical differences are difficult for the rider to spot. Personally, I have always admired the profile of the Tarmac frame. It looks burly without being overdone when compared with many other modern carbon frames which can at times look so oversized that it is almost a novelty. The Tarmac cuts a classic and elegant profile while still looking modern.

The first thing I noticed when I swung my leg over the top tube of the Tarmac is that this frame has some major real estate in the top and down tubes, despite the classic side on silhouette. The top tube flares out so that it is significantly wider than the head tube that it joins. It literally engulfs and swallows the top part of the head tube. Specialized refer to this as a Cobra top/head tube junction, and the top tube does resemble the flared and flattened head of a Cobra. The down tube, although rounder in shape, also has a larger diameter than the head tube. The whole point of this is to enhance torsional rigidity through the front of the frame for direct steering. Specialized claim that surrounding the head tube with the wide embrace of the top and down tubes gives the best stiffness relative to the volume of material used to make the tube shape.

The less obvious frame feature is the head tube and fork. Bigger isn’t necessarily better, and Specialized have reduced the lower bearing from 1 1/2 inch to 1 3/8 inch. It’s a small change that Specialized claim offers a smoother ride without sacrificing rigidity. Other well-known makers such as Focus and Cervelo already use lower bearing diameters between the traditional 1 1/8 and the in vogue 1 1/2 inch. It’s interesting that Specialzed have decided to downsize in favour of ride quality in this bigger is better market.

In any case, it only takes one ride to know that the Tarmac is 100% committed to going where you want it to go. The fork blades are thick and the front wheel tracks precisely when lent over hard or being shimmied around in a clumsy maximum effort sprint. From front to back the Tarmac is as solid as a rock. As much as an all around race machine needs to climb, the Tarmac shows its true colours when the road points down. One particular descent stuck in my mind. Cork screwing down into a small valley the rider is faced with three sharp and steep 90 degree corners with the middle corner slightly off camber. The Tarmac railed through the choppy road surface and middled itself in anticipation of the next corner where other bikes have twisted and twanged in the commotion of gravity and direction changes.

The Expert level Tarmac is an accessible mid level bike, but it is unequivocally the descendant of a premium race bike. The price point shouldn’t confuse recreational riders into thinking the Expert is for recreational coffee and banana bread riding. The rider position is aggressive and the bike responds best when you grab a fist full of the drops, stretch your outside leg and weight the pedal and lean in as hard as you dare. She loves it! Bomb the descent, regain your composure as your adrenalin haze subsides, then crack on with a good cadence towards the next high speed party. The Expert also has the feel of a quality race machine. You can detect every seam in the road and almost imagine the texture of the surface based on the feedback that you receive through the bar, pedals, and saddle, but it’s not a nasty ride that leaves you beaten up after a few hours. The Expert gives the rider all of the information they need rather than making the decisions on their behalf.

Just as Specialized offer a large range of highly regarded apparel, the Expert is clothed extensively in Specialized branded components. This allows Specialized to control the entire fit and feel of the bike as well as to offer a bike that is conceived as a total package from A to Z, and at a decent price point to boot. The Expert complete bike really is all about getting the rider onto a premium frame with blue collar parts that offer solid performance, but also offer room to upgrade over time. The Expert wouldn’t look out of place with Red or Dura-Ace fitted, but the Ultegra drivetrain is an echo of the frame: close to pro performance at a fraction of the price. Specialized have spec’d a BB30 FSA crank with 52/36 rings and an 11-28 105 cassette. The range is super broad, so the Expert will have you covered whether you’re a climber or sprinter. That said the 36 tooth inner ring may frustrate stronger riders that ride with a high cadence and tempo and are used to doing most of their k’s in their 39/18 or similar. But that would be a minority.

The ergonomics of the Expert are excellent out of the box. The Toupe saddle is flat in profile and has a moderate amount of padding. It didn’t look like the kind of saddle that I usually make friends with but I only found myself pining for my own saddle (a Specialized Romin) after extended periods on the flat with my hands in the drops, when I got a little numb. The stem and post also warrant mention. The stem has a removable shim that allows the angle to be altered so that you can fine tune the position of your bars. It’s a really nice touch and it’s Specialized’s way of telling you that you should make the effort to get your riding position just right. The post is just a post, but it’s a skinny 27.2mm post, which allows more in-post flex to take the sting off rough roads.

The DT Axis 4.0 wheels are only available on Specialized bikes. The hubs are not DT made but are a well made generic unit with sealed bearings and alloy axles and should last well. The high spoke count and traditional j-bend spokes also point to durability and the Axis 4.0’s weigh just over 1700g. Unfortunately, both front and rear wheels on our test bike were not quite true once the bike was built up it. On inspection there were several insufficiently tensioned spokes and many of the nipples had their heads partially ground off by the wheel assembly machine.

Bicycling Australia contacted Specialized about this problem and immediately another set of wheels was on the way. Our representative at the big S reported that they hadn’t had any reported issues with these bikes and hoped that our test wheels were an unfortunate one off. At any rate, we were impressed with the speed of the response, which indicates good respect for the customer.

Regardless of the price point or components, the Expert frame delivers a race focused performance that highlights its DNA. The front to back stiffness of the frame enables aggressive descending and the road feel gives a confident rider more than enough information to safely push their limits without being beaten to a pulp after 60 minutes. The complete bike is a great value way to enter a top performing chassis and is a solid privateer bike in stock form.

Quality

The Expert frame is nicely finished, nothing to worry about here. Its even got all the cable ports for tidy electronic cabling for the future. All of Specialized’s in house parts are well thought out and perform without fuss, and Ultegra is the default for consistent performance at a price point. The quality control on the wheels was slightly disappointing.

Value

Many will look at the Expert and see a carbon bike with Ultegra at $4,000. This is a ferocious segment in the market, and on paper there are plenty of better value alternatives. The pro level performance of the frame brings an extra element to the equation: you can easily spend this amount just on a frame that offers similar or inferior performance to the Expert frame. The Expert offers a great ride which, if required can then be further refined over time with upgrades.

Performance

Direct feel lets the rider know what’s going on under your tyre, but it’s not so direct that you’ll have sore fingers the next day. End to end, the Tarmac is solid and predictable. It’s a go fast machine without being suicidal to ride. The Ultegra spec is bullet proof and leaves you to worry about your personal performance rather than that of your equipment.

Overall

The Expert looks like a middle of the range bike, but there is a wolf somewhere under the polite silver sheep suit. Excellent road feel and frame stiffness offer a bike that suits fast paced and aggressive riding. The Expert is up for anything, and has plenty of room to upgrade. This is a great bike for the privateer that is less concerned about having S-Works painted on their down tube than getting in the saddle and pushing the limit of their own performance metrics.

Specifications

Frame: Specialized FACT 10r carbon, FACT IS construction, tapered/shaped HT, compact race

Fork: Specialized FACT carbon, full monocoque, OS race for 1 3/8″ bearing

Headset: 1-1/8 upper and 1-3/8″ lower stainless steel cartridge bearings integrated w/ headset, 8mm cone spacer with 20mm of spacers

Stem: Specialized Comp-Set 6061 alloy, cone head bolt, 12-degree, 4-degree shim, 31.8mm

Handlebars: Specialized Tarmac Expert, 2014 alloy

Front Derailleur: Shimano Ultegra

Rear Derailleur: Shimano Ultegra

Brakes: Shimano Ultegra

Shift Levers: Shimano Ultegra STI

Cassette: Shimano 105, 10-speed, 11-28

Chain: KMC