Anyone who rides a racing bike not just for fun, but also for victory or personal best times, has been faced with a dilemma until now. There has never been a bike that is perfect for every conceivable race course. If the course is predominantly uphill, a mountain racing bike that is as light as possible is ideal. If the course is flat to undulating and possibly ends with a sprint finish, everything speaks in favour of a bike that is as aerodynamic as possible. Leaving aside special cases such as the Paris-Roubaix cobblestone race, which in turn places special demands on the material, every ambitious racer strictly speaking needs at least two racing bikes.
New Tarmac SL7 to be a mountain and aero road bike at the same time
But now, with the new Specialised S-Works Tarmac SL7 a racing bike that aims to resolve the contrast between light and fast once and for all. The brand from Silicon Valley praises its new top product as the "most complete Tarmac ever". What's more, owners of the Tarmac should never again have to worry about what kind of racing bike they are riding. The new Tarmac is designed to be as light and agile as a climbing machine and as fast as an aero road bike. Taken to its logical conclusion, this means that the road bike is the Aero model Vengewith which Specialized has been one of the driving forces in road bike construction in recent years, should actually be obsolete.
Looks are deceptive: frame and stem of the Specialized Tarmac SL7
In view of the spectacular announcement, the Specialized Tarmac SL7 seems almost inconspicuous when you stand in front of it. Formally, there is little to suggest that it could be aerodynamically inferior to the Venge. Only the seat tube and the seat post have a profile that is recognisable as aerodynamically favourable at first glance. The cross-section of the comparatively slim down tube is not really round, but also does not have the typical Kammtail profile with hard tear-off edges that has become established in aerodynamically optimised racing bikes in recent years.
The developers were also remarkably restrained when it came to integrating the components around the frame. While the fork of many competitor models merges positively with the frame, the Tarmac fork could also be fitted to any normal round tube frame. The Conventional stem has been formally adapted to the frame and guides the brake lines almost invisibly into the frame. However, it clamps the handlebars conventionally, which makes position adjustment and transport somewhat easier than a fully integrated handlebar cockpit. A service-friendly BSA threaded bottom bracket rounds off the almost conservative design approach off. You can't help but wonder where the spectacular aerodynamics that Specialized promises for the Tarmac SL7 are supposed to come from.
Aero-inspired: Handlebars and wheels of the Specialized Tarmac SL7
However, there are a few formal peculiarities. The one taken from the Venge Aerofly 2 handlebars is unusually wide at the upper handlebar. To maximise the aerodynamic advantage of the shape, the handlebar tape is only wrapped to just above the brake levers. In addition, the upper handlebars have a rough, textured surface structure, similar to the dimples on a golf ball, which are intended to prevent turbulence from causing braking. The rims are also unusual. With the brand new Rapide CLX wheels Specialized's own brand Roval, the designers took up an idea that first appeared two years ago on Cannondale's SystemSix aero road bike. In particular, the front rim of the Roval wheels is significantly wider than the tyre and measures an impressive 35 millimetres at its widest point. This takes some getting used to, especially from the rider's perspective, as the half of the tyre facing the road is completely covered by the rim. However, the Cannondale SystemSix (TOUR 1/2019). So far, the bike is the fastest that TOUR standard was measured.
<<All details on the TOUR test procedure, the most elaborate test protocol in the cycling industry>>
The predecessor model: Specialised S-Works Tarmac SL6
Enough of the descriptions and mount up for a test drive. For those who Predecessor model Specialised Tarmac SL6 will have a good idea of how the new Tarmac rides. The SL6 received almost exclusively very good to enthusiastic reviews for its riding behaviour. Although it is significantly slower aerodynamically than the Venge, most of the pros on the Bora-hansgrohe and Deceuninck - Quick-Step teams equipped by Specialized have preferred the Tarmac in the last two seasons.
Its geometry has been adopted one-to-one in the new model. The Seating position is clearly race-orientatedbut not too extreme. With a wheelbase of just under one metre and a short fork trail, the bike is very agile. Thanks to the high frame stiffness, it stays precisely on course in every riding situation. The seat post offers exactly the right amount of flex that is desired on a professional racing bike. Not too hard to effectively filter out tarmac patches and gully covers. And not too soft, so that the power of the legs is channelled into propulsion instead of deforming the seatpost.
The Specialized Tarmac SL7 in the world's first practical test
Specialised provided TOUR with two Tarmac SL7 road bikes for the test. In addition to the Standard model with SRAM Red AXS drivetrain in size 56 also a Original professional bike of the German sprinter Pascal Ackermann from Team Bora-hansgrohe in frame height 54 including Dura-Ace Di2 equipment from Shimano. The latter should have originally taken part in the test of the 13 professional bikes in TOUR 8/2020. However, because Specialized had to postpone the presentation of the new Tarmac SL7 due to the coronavirus crisis, we were unable to show the bike there. On the one hand, this is a shame, but on the other hand it gives us the opportunity to present the bike in detail here.
The original professional bike from Pascal Ackermann
One interesting aspect is the comparison between the different sizes of the two bikes. Although Pascal Ackermann and the TOUR tester are almost exactly the same height, the Bora sprinter rides the frame one size smaller. The shorter top tube of the 54 mm frames he compensates with a 140 millimetre long stem. In fact, the Distance between saddle and handlebars only 18 millimetres longer on a professional bike than the standard setting on the 56 mm frame with 110 mm stem. The significantly lower handlebar definitely allows for a more aerodynamic, faster riding position. The increase in speed, especially with a forced riding style, can be clearly seen in the riding data.
However, we covered considerably more test kilometres on the 56 series Tarmac. One particularly beautiful tour took us over Monte Baldo to the east of Lake Garda. On this demanding tour with 1900 metres of elevation gain, the bike lacked nothing in terms of climbing qualities.
Even slightly lighter wheels than the Rapide CLX 60 would perhaps make the Tarmac a little more lively on the climbs. But whether this would ultimately lead to the summit faster is questionable. On the winding, 17-kilometre descent into the Adige Valley to Avio, the stable disc brakes from SRAM played their trump card. Here too, the choice will be easy for both professionals and customers in the future: while a version with rim brakes was offered in parallel with the SL6, the SL7 will only be available with disc brakes.
Specialized S-Works Tarmac: The best road bike in the world?
Finally, perhaps the most exciting question about the Tarmac SL7 remains: is it really as good aerodynamically as Specialized promises? We investigated this in the GST wind tunnel at Airbus on Lake Constance with the rider dummy with rotating legs developed by TOUR. The test result confirms Specialized's promise. With good 210 wattsthat must be applied to overcome the aerodynamic drag of the bike at 45 km/h, the Tarmac SL 7 is very close to aero road bikes such as the Cannondale SystemSix, Cervélo S5, Canyon Aeroad, Specialized Venge and Giant Propel, which achieve values between 203 and 208 watts. Aerodynamically, the Tarmac SL7 is therefore at the level of the Pinarello Dogmawhich has been winning tours by subscription for years. However, with disc brakes, it is as light as the Dogma with rim brakes and significantly more comfortable. The Tarmac SL7 not only compensates for the small aerodynamic gap to the pure aero specialists with its Low weight (6.8 kilos with Dura-Ace Di2, 6.9 kilos with SRAM Red AXS). Above all, it rides much more balanced and should therefore come close to the perfect road bike for many types of riders. In the end, this is also reflected in the test score. One Overall grade of 1.4 have only been awarded once so far. That was in 2016 at the Canyon Aeroad CF SLX (to the test) with rim brakes. As Canyon no longer offers this bike, at least with the lightweight SLX frame, the Tarmac SL7 can therefore claim the title of best racing bike in the world for themselves. But it remains exciting. A competitor of Specialized will soon be presenting a racing bike that could challenge this title.
Factsheet: All the details about the Specialized Tarmac SL7
The Specialized Tarmac SL7 is now available in seven frame sizes from 44 to 61 centimetres. The two top models of the S-Works series with SRAM Red AXS or Dura Ace Di2 equipment are based on a particularly light carbon frame, weighing 857 grams according to TOUR measurements, and cost €11,499 each. The S-Works frame set is available for 4199 euros and, like the complete bikes, is designed exclusively for electric shifting systems. Below this, Specialized offers several other model variants whose frames are made from simpler carbon fibres and are therefore somewhat heavier. The entry-level model is the Tarmac SL7 Expert with mechanical Ultegra gears and carbon wheels for €4999.
- S-Works Tarmac SL7 - SRAM Red eTap AXS - 11499 Euro
- S-Works Tarmac SL7 - Dura-Ace DI2 - 11499 Euro
- Tarmac SL7 PRO - SRAM ForceETAP AXS 1X - 7399 Euro
- Tarmac SL7 PRO - Ultegra DI2 - 6999 Euro
- Tarmac SL7 Expert - Ultegra DI2 - 5299 Euro
- Tarmac SL7 Expert - 4999 Euro
Technical data/equipment
- Frame/fork/headset bearing weight 857/374/63 grams
- Frame sizes 44, 49, 52, 54, 56, 58, 61 cm
- Seat/top/head tube 500/560/163 mm
- Stack/Reach/STR 567/392 mm/1.45
- Wheelbase/caster 990/56 mm
- Drivetrain/gear system SRAM Red AXS (48/35, 10-33 t.)
- SRAM Red brakes (160/160 mm)
- Wheels/tyres (weights) Roval Rapide CLX 60/Specialized Turbo Cotton 26 mm
- mm (front/rear - 1134/1450 grams)
Measured values & individual scores for testing the Specialised Tarmac SL7
- Air resistance: 210 watts - Grade 1.7
- Weight complete wheel: 6890 grammes - Grade 1.7
- Steering head stiffness: 98 Nm/°- Grade 1.0
- Lateral stiffness fork: 53 N/mm - grade 1.0
- Bottom bracket stiffness: 58 N/mm - grade 1.3
- Seatpost spring stiffness: 156 N/mm - grade 1.7
