Stages Cycling’s new carbon crank works with both SRAM and FSA cranksets. Stages debuted the first left-arm crank-based power meter in 2012, but the new model is a world first for a carbon crank with a power meter built onto it.
The crank works as is with FSA cranksets, and with one of four spindles for compatibility with SRAM Red, Force/Rival, and two widths of mountain bike options.
The Stages Carbon is ANT+ and Bluetooth Smart compatible.
Stages Carbon Power Meter – First Look
Stages introduces carbon crankarm power meters
To crack the carbon conundrum, Stages had to overcome several hurdles. Issues stymieing the quick production of a carbon Stages meter included difficulty in bonding to a composite material, temperature compensation and different fatigue characteristics.
“We could have made a carbon power meter a long time ago, but it would have had the functionality of a meter from the pre-Stages era,” Sam Morrison, Stages Cycling engineer and carbon product manager said. “The problem isn’t measuring deflection in carbon, it’s dealing with changes of the material when the operating temperature changes. We could have easily released a meter that would require constant and vigilant zero resets; rather, we took our time and built a new system to specifically deal with the challenges carbon faces when temperatures change.
“What we’re delivering is a fully functional Stages power meter for carbon cranks, and we’re proud of that. We made no concessions.”
The carbon Stages units use an entirely new strain gauge developed to measure deflection of carbon cranks to the same level of accuracy as the Tour de France-winning alloy models, while also maintaining automatic temperature compensation.
Stages Cycling carbon crankarm
The new stages cycling carbon crankarm is compatible with bb386evo and bb30 (road and mtb):
With SRAM owning the power meter brand Quarq, it’s no surprise that there are no SRAM-branded carbon Stages crankarms available. To address SRAM riders, Stages developed its first own-brand crankarm with FSA.
The new Stages crankarm is made of hollow carbon and features a shape very similar to that of SRAM’s models. The crank is natively compatible with FSA’s BB386EVO cranksets, while Stages is also offering three aftermarket spindles with a SRAM-style asymmetric interface. This allows compatibility with SRAM Red, BB30 and 168mm SRAM MTB setups depending on the spindle length selected.
Available in 165-175mm lengths, the Stages crankarm is available now for £599 / $699 with your spindle of choice. A GXP version is also available.
The second-generation meter’s housing is 5mm thick compared with the previous model’s 8mm, meaning better compatibility with under-mount brakes. Stages is claiming a 28 per-cent lower profile and 17 per cent reduction in frontal area, resulting in a sleeker look overall. This final production module also has a little more structure than seen on Froome’s prototype.
A key upgrade for those who might’ve been alerted to water-ingress issues with the old housing is a redesign of the battery cover. The new cover has a wider diameter and more robust fastening. Stages says this new design increases the strength of the battery door and housing interface by 200 percent.
BikeRadar is now testing a Stages Carbon meter and will post a full review soon.
Inside the Stages Cycling factory – How a Stages power meter is made