February 04, 2014
There is little doubt that over the past few years, power and Watts have established themselves as supremacies for gauging effort, and therefore relative physical exertion, during a training ride. Relatively unaffected by outside influences such as temperature, wind and heart rate, power is widely regarded as the most consistent and reliable way of tracking physical fitness and development.
Pioneering systems such as SRM have in recent years been increasingly challenged for market space, by the like of Powertap, Quarq, and Garmin Vector with their alternative approaches to power measurement.
Stages Power Meter
But latest to join the party is the Stages Power meter. First rolled out in prototype form at the back end of 2012, Stages have now reintroduced their power meter after crossing the T’s and dotting the I’s, into a market craving…exactly what they’ve produced; an alternative which revolves around principles of both practicality and price.
Where their crank-based predecessors have opted to take measurements from the spider, Stages’ technology lies solely within the left-arm crank. The main principles of such a move being to keep two defining factors to a minimum: complexity and cost.
The system relies on the assumption that both legs are outputting the same wattage, which some users may question. Stages’ reasoning for justifying this assumption is as follows, though:
“Our assumption of symmetry gives major advantages over spider based torque measurements, which are forced to add complex algorithms or geometries in order to filter out unwanted torque measurements coming from chain line and crank position.
Our left measurement also makes our calibration simpler and more accurate, due to the fact we do not have to compensate for torque differences due to chain line induced flex in the spider or chain ring stiffness.”
P+2*((Fave*9.8*L)*(R*.1047)), where P = power, is that “simple” equation in question, for those who were wondering.
Moving on though, the other benefit of such compact hardware is of course weight, with the entire unit coming in at an astonishing 20g – between 33 and 185g less than its competitors…before any additional hardware has been accounted for – of which the Stages Power meter requires none (for cadence, it uses an inbuilt accelerometer to track crank rotation.)
Another revolutionary development that Stages have pioneered is enabling variable ways to transmit data, by giving users the possibility of using both ANT+ transmission (Garmin), as well Bluetooth 4.0 for use with smartphones. They don’t provide their own head unit, so users will have to own one of the compatible appliances.
But do the cut backs that Stages have made affect the reliability of their results? Here’s a line graph analyzing Stages’ output data in comparison with a competitor (the identity of which is naturally undisclosed!)
Our take on the Stages Power meter
The Stages Power meter is potentially going to be a big success; a power meter with a simplicity factor incomparable to any of its more expensive competitors, yet which also appears to produce results equally as reliable.
There is an ever increasing demand for product ranges aimed at keen, regular cyclists who want a reliable way to track their progress as a rider. This is the market Stages Power is primarily aimed at, but from what we can see Stages can expect to be punching well above their weight.
We currently have Shimano 105, Ultegra, and Dura Ace versions in stock, for £599, £699 and £799 respectively.