Magene P515 Power Meter: Best Sub-$300 Dual-Sided Crank Option in 2026

The Magene P515 is the most interesting power meter released in the sub-$300 bracket since the Favero Assioma launched in 2018. It is the first Chinese-designed dual-sided crank power meter to ship at retail, and after two months of testing it is finally a legitimate Assioma alternative — not just on price, but on accuracy.

Magene has been making power meters since 2019, starting with the P505 (single-sided) and P605 (pedal-based). The P515 is their first crank-based dual-sided design, and it is positioned squarely at the Assioma DUO buyer who would prefer to keep their existing pedals.

Key Specifications

• Dual-sided crank power measurement
• Claimed accuracy ±1.5% (third-party verified)
• ANT+ and Bluetooth LE
• Rechargeable 150-hour battery via magnetic USB-C
• IP66 water resistance
• Available in 165 / 170 / 172.5 / 175 mm crank lengths
• BSA / BB86 / T47 / PF30 bottom bracket compatibility
• OTA firmware updates via Magene Utility app
• $279 USD MSRP for the crank arm set

Build & Design

The P515 ships as a pair of replacement crank arms. The strain gauges are integrated into the spindle area, sealed behind a stainless cap. The visual design is unobtrusive — a small status LED on the inside of each crank blinks blue during pairing and green when measuring. The rechargeable battery is sealed inside the spindle; you top it up via a magnetic USB-C puck that snaps onto the non-drive-side crank.

Installation is straightforward for anyone comfortable swapping a crankset. Magene includes a one-piece spider tool and clear instructions. The unit weighs 89g added over a stock Shimano 105 crankset, which is heavier than the Assioma (zero weight change to pedals) but lighter than the Quarq DZero (~150g).

Real-world Testing

Two months of structured training, including a 600km brevet and 12+ Zwift sessions, gave a clear picture. Pairing with every head unit tested (Garmin Edge 1040, Wahoo Roam v2, Hammerhead Karoo 3) was instantaneous. Battery drain averaged 0.6% per hour, on track for the 150-hour claim.

Side-by-side against a Favero Assioma DUO on the same bike, the P515 was within 2-3 watts at threshold, within 1-2 watts on steady-state tempo work, and within 5 watts on 5-second sprints. Temperature compensation worked as advertised across a 0°C to 32°C test range.

Left-right balance accuracy is the headline feature for a dual-sided crank in this price bracket. The P515 reported balance within 1% of the Assioma DUO across all tested efforts. That is more than good enough for training and racing.

Pros

• Sub-$300 price for a true dual-sided crank
• Rechargeable 150-hour battery (no coin cells)
• Excellent left-right balance accuracy
• Wide BB compatibility (BSA / BB86 / T47 / PF30)
• Magnetic USB-C charging — no port cover to lose
• OTA firmware updates

Cons

• Crank-specific (not transferable between bikes with different cranks)
• Heavier than pedal-based alternatives
• Magene Utility app is functional but rougher than Favero or Garmin
• Status LED on inside of crank is slightly visible in some pedal-stroke angles
• Limited global service network compared to Favero or Quarq

Verdict

The Magene P515 is the new default recommendation for riders who want a dual-sided crank power meter without paying Favero Assioma DUO money ($599). The accuracy rivals the Assioma across all tested metrics, and the rechargeable battery is a real win for daily users. Riders who want to keep their pedals free should still consider the Assioma DUO. Riders who want the absolute lowest price and are comfortable with left-only should consider the 4iiii PRECISION 3. For everyone else, the P515 is the sweet spot in 2026.