Pioneer launched 2 new single-arm power meter models at Interbike. They have actually been around for a while now, but were previously only offered as a pair.

Pioneer now offers single-arm Ultegra ($799) and Dura-Ace ($899) models, with the option to upgrade to their full dual-leg version that we previously reviewed. The single-arm option is offered as a more affordable starting point as more and more cyclists are using power. What distinguishes this system from other single-arm power meters is the ability for the consumer to upgrade with an add-on kit ($699) to provide dual-leg power without the need to buy a new system or new power meter, plus Pioneers offers exhaustive cycling metrics.

Users will still need a Pioneer head unit to take advantage of the HD metrics, but can use an Ant+ bike computer for basic metrics. The single-arm version is reported to add only 22 grams to the weight of the crank arm and will provide all the same metrics of their dual-leg system, except for metrics that require dual-leg data such as left/right power and pedaling balance. It also gives the user the ability to adjust the estimated total power based on any pedaling imbalances so that total power estimated will provide a more accurate representation.

The Pioneer single-arm power meter weighs in at just at 22 grams.

Hidden behind the non-drive side crank, the power meter looks very subtle.

Pioneer has also updated Cyclo-Sphere (online software) and their Cycle Computer to include TrainingPeaks metrics such as Training Stress Score (TSS), Intensity Factor (IF), and Normalized Power (NP). Recent updates also include a mobile version of Cyclo-Sphere and the ability for users to switch between Pioneer's HD Ant+ and standard Ant+ via the Cycle computer. They have continued to solidify their hold in cycling metrics with other additions for users such as graphic gear and battery status on the Cycle computer, and post-ride analysis of Di2 gear ratio analysis, shift intervals, total shifts (front and back), and analysis based on seated or standing positions. Pioneer also updated their dual-leg system. Recent updates included the slimming of their units to allow for greater clearance so the units are compatible with most frames, and improved ease of the initial installation. You can find this system on the bikes of Tim Reed, Jeff Symonds, Eric Lagerstrom, and Leanda Cave, just to name a few.

The new single-arm power will begin shipping by the end of September 2015 and the hardware updates to the dual-leg version have been effective since June 2015.