Stages reveal carbon crankarm power meters

Second generation Stages enclose with carbon options for Campagnolo, FSA and SRAM drivetrains

This article originally appeared on BikeRadar

Stages Cycling has revealed carbon crankarm versions of its single-sided power meter at Eurobike, along with a new smaller housing, which will be phased in across the whole range.

Stages introduces carbon crankarm power meters

With its cracking of the carbon conundrum, Stages has added compatibility for Campagnolo Super Record, Record and Chorus as well as FSA SL-K Light and SRAM – the latter via Stages' first own-brand crankarm.

Up until now, Stages' power meter technology has been exclusively available to riders running alloy crankarms. Stages says the company has been working on a carbon version for years, but has had to overcome several hurdles before bringing the finished meter to market. Issues stymieing the quick production of a carbon Stages meter included difficulty in bonding to a composite material, temperature compensation and different fatigue characteristics.

Sam Morrison, Stages Cycling engineer and carbon product manager, said: "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.

"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


With SRAM owning Quarq, it's no surprise that there are no SRAM-branded carbon Stages crankarms available (the alloy Rival and X9 models are also being phased out). In an attempt to corner this market, Stages has developed its first own-brand crankarm in partnership 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 and with a claimed weight of 140g, the Stages crankarm is due in January 2016 and will cost €799 or €899 with your spindle of choice (regional pricing TBC). A GXP version is due in early spring 2016.

Campagnolo


Stages says compatibility with Campagnolo has long been sought by users of the Italian groupsets who don't wish to compromise on the sleek looks of the stock cranks. It's understandable given the less-than-stellar visuals of Power2Max equipped Campag spiders such as those used by Nairo Quintana.

Campagnolo crankarms equipped with Stages will cost €899 for Chorus, €999 for Record and €1199 for Super Record. All Campag models will be available in 170-175mm lengths and are due to hit the market in February 2016.

FSA SL-K Light


FSA's SL-K Light BB30 carbon crankarm is also available with Stages on board. Available in 165-175mm lengths, it's due in January for €799.

Second generation Stages enclosure


We spotted a prototype version of a new Stages power meter on Chris Froome's bike at the Tour de France. The American company was also showing the finished article at Eurobike, which will feature on all carbon versions and is due to be phased in across alloy crankarms too.

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.

The second-generation meters will be available in Shimano options from September with other types following suit before Christmas.

Check out more news from Eurobike at our Eurobike homepage.

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