Specialized debuts S-Works Power Cranks and Tarmac Disc

Last week, Specialized unveiled the new Tarmac Disc and a crank based power meter. The Tarmac disc was a long time coming after being seen under pro riders since the beginning of the season. The Specialized Power Cranks have also been used in the pro ranks by Peter Sagan’s Bora-Hansgrohe team now seeing the light of day for everyday riders. Now we have all the details of the new frame and power meter.

Specialized Power Cranks

The release of the new Specialized power meter gives cyclists an even wider range of choices when it comes to choosing how to measure the watts you are producing on your bike.

The Specialized Power Cranks is a dual-sided system with a pod on the inside of the non-driveside crank and another in the chainrings. The power meter has a accuracy of +/- one per cent. The power meter provides dual sided unidirectional power measurements allowing users to analyze the power metrics from both legs independently. The power meter was developed in a partnership with Cochrane. Alta. based 4iiii.

The Power Cranks will be avaialble on Shimano Dura-Ace, Ultegra and 105 cranks. Not surprisingly it will also be on S-Works carbon crank, which Specialized says is the first time direct measurement dual-sided powermeter is made commercially available on a carbon crank. There will also be dual and single side aftermarket options. The dual sided Power Cranks on the Specialized carbon crank will come stock on the  S-Works Tarmac Disc.

Specialized also boast the Power Cranks are the lightest power meter available weighing 440 g for the 172.5 mm crank length version. They will be available on cranks for 165 mm to 180 mm. The power metre can be installed on frames with OSBB or PF30 bottom bracket shells and most BB30 road frames. The power meter connects through ANT+ and BLE with calibration done through a Specialized app or using a head unit.

Weather sealing was also an important factor since pro riders subject their power meters to a variaty of conditions and team mechanics are washing bikes daily.

The new Tarmac Disc

The new Tarmac disc looks remarkably similar to the rim brake model. This was done intentially with Specialized working to keep the same frame geometry despite the addition of dis brakes using what Specialized call the Rider First Engineered design. Specialized hope the concept allows bikes of various sizes to maintain the same ride feel. The Tarmac was overhauled last year with new tubing shapes for better aerodynamic performance, a lighter frame and more features to add to rider comfort.  Across all sizes, the Tarmac Disc has 410 mm chainstays. Aerodynamically, the frame hasn’t changed though the bike has been in development for five years.

The bike comes equipped with tru axles front and rear. Spacing is 10 x 100 mm in the front and 12 x 142 mm in the rear. The Flush Axle System is a bolt on system without any levers. The bike will also come with DT RWS levers so riders can choose which system they prefer.

While Specialized did their best not to add any weight to the frame, a complete Tarmac Disc weighs in at 6.65 kg which is slightly more than the 6.36 kg the rim version tips the scales at. The disc version comes with the S-Works Power Cranks. The disc version can also take marginally wider rubber able to accomodate 30 mm tires.

Stay tuned for pricing and Canadian availablility details.