Best road bike in the world: Specialized Tarmac achieves new TOUR top score

So far, four competition models have topped the list of the best racing bikes in the world. The Canyon Aeroad, Giant Propel, Scott Foil and Specialised Tarmac SL7 in exclusive equipment variants earned the best TOUR score to date thanks to top performance in the four most important criteria. The 1.4 seemed to be set in stone, the symbiosis of aerodynamics, weight, comfort and stiffness could hardly be improved. However, Specialized has now set a new record with a great piece of engineering - and provides a glimpse of the direction in which competition racers are likely to develop.

Tarmac SL8: Perfect symbiosis

Making one of the already best road bikes in the world even better: This was the task facing Specialized around the Freiburg Chief Engineer Peter Denk and remained true to its philosophy. Among the competition all-rounders, the SL8 remains the bike that has no weaknesses in the exclusive S-Works version. The bike already showed its potential during the first ride test on the fringes of the World Cycling Championships in Glasgow. The measured values from the TOUR laboratory and GST wind tunnel now confirm the riding impression. The bike impresses above all with the perfect interplay of its characteristics.

>> Click here for the English test report of the Specialized Tarmac SL8

Thanks to its low weight of 6550 grams, the Tarmac accelerates as if pulled by a string and sprints up climbs with ease. The extremely torsion-resistant frame set and the sporty, stretched seating position emphasise the character of the thoroughbred racer. In contrast to our test bike in Glasgow, which was equipped with a saddle from the 3D printer, the graded version with a conventional carbon saddle is somewhat less comfortable. Overall, however, the SL8 offers a high level of suspension for a competition bike.

In the GST wind tunnel in Immenstaad the Specialized finally dispelled all doubts: with 209 watts of pedalling power required to overcome the air resistance at 45 km/h, the new bike is only slightly faster than the SL7 (210 watts). There are also competitors with better aerodynamics or more comfort. However, as an overall concept, no road bike currently works better.

The fastest production bikes in the TOUR test

The fastest road bike in the TOUR test, the Simplon Pride II (199 watts), the Tarmac SL8 lacks exactly ten watts. However, the aero bike from the Austrian bike manufacturer is also more than a kilogram heavier and more rigidly tuned, which is why it cannot keep up with the agile handling of the Specialized.

Compared to similar all-round concepts such as the Cannondale SuperSix (207 watts) or Van Rysel RCR (207 watts) the Tarmac is almost on a par in terms of aero performance. However, both the bike from the US competitor and the new product from Decathlon's own brand also weigh more and are less stiff.

Expensive fun

However, the price tag of the new record holder puts a stop to the euphoria. The S-Works Tarmac SL8 with electronic Dura-Ace and aero wheels from the in-house brand Roval is slightly cheaper than the previous model. However, 14,000 euros is still a lot of money for a racing bike - as good as it is. Cheaper versions are between 6800 and 9000 euros, but they do not come close to the impressive driving experience of the top model.

Specialised S-Works Tarmac SL8

• TOUR grade: 1,3
• Price: 14,000 euros >> available here

Weights & geometry

• Weight frame/fork/steering bearing*: 723/383/58 grammes
• Frame sizes**: 44, 49, 52, 54, 56, 58, 61
• Seat/top/head tube: 495/565/159 millimetres
• Stack/Reach/STR***: 574/389 millimetres/1.48
• Wheelbase/caster: 990/60 millimetres

Equipment

• Drive/gear shift: Shimano Dura-Ace (2x12; 52/36, 11-30 teeth)
• Brakes: Shimano Dura-Ace (160/140 millimetres)
• Wheels/tyres (weights)****: Roval Rapide CLX II/S-Works Turbo Rapidair 2BR 26 millimetres (front/rear: 1136/1438 grams)

Measured values & individual grades*****

• Weight of complete wheel: 6.6 kilogrammes | 1.3
• Steering head stiffness: 106 Nm/° | 1.0
• Lateral stiffness fork: 55 N/mm | 1.0
• Bottom bracket stiffness: 61 N/mm | 1.0
• Seatpost spring stiffness: 156 N/mm | 1.7
• Aerodynamics******: 209 watts | 1.7

The TOUR grading scale

The TOUR grading scale is based on what is technically possible and sensible. For example, we award a score of 1.0 for weight if the road bike is lighter than 6.3 kilograms. The same applies to the criteria of stiffness and comfort - the benchmark here is what is technically feasible. It is not desirable to make a road bike infinitely stiff. A score of 1.0 is achievable in this discipline, but the values are capped. An overall score of 1.0 for a bike is theoretically possible; however, as individual criteria such as weight and aerodynamics require opposing design measures, the challenge remains high.

With the advent of electric gears and disc brakes, we have adapted our grading scale to take account of technical progress. This also applies, for example, to current tyres with better technical properties. The new top score of 1.3 can therefore no longer be compared with older bikes that achieved this score with rim brakes and mechanical gears.

• *Weighed weights
• **Manufacturer's specification (test size bold)
• ***Stack/reach: projected vertical/horizontal measurement from the centre of the bottom bracket to the top of the head tube; STR (stack to reach): 1.36 means a very stretched, 1.60 an upright sitting position
• ****Wheel weights including tyres, cassette, quick release/threaded axles and brake discs if applicable
• ***** For reasons of space, we only print some of the individual grades, which are weighted differently in the overall grade. The grades are calculated with all decimal places up to the final grade; however, for the sake of clarity, all grades are shown with rounded decimal places
• ******Aerodynamics: theoretical pedalling power required to overcome the air resistance at 45 km/h, measured in the wind tunnel with a pedalling leg dummy