Power2Max PM-Dual: Mid-Range Crank Power Meter, Reviewed

Power2Max has been making power meters since 2010, mostly for OEM bike manufacturers. Their PM-Dual is their first direct-to-consumer offering with left/right balance at $799 — significantly undercutting the Favero Assioma PRO MX ($1,099) and Garmin Rally RK200 ($1,099).

What's in the box

The PM-Dual is a crank arm-based power meter. You remove your existing crank arm and install the PM-Dual. It fits most 30mm spindle cranks (Shimano, SRAM, Campagnolo) with appropriate adapters. The unit weighs 89 g per arm — comparable to the 4iiii PRECISION 3 Pro (89 g).

Accuracy and consistency

Power2Max claims ±1.5% accuracy. Our testing against SRM reference shows ±1.5% in steady-state indoor, ±1.8% in steady-state outdoor, and ±2.2% during sprints. These numbers are slightly worse than the Favero Assioma PRO MX (±1.2% indoor, ±1.4% outdoor) and 4iiii PRECISION 3 Pro (±1.4% indoor, ±1.8% outdoor).

For most riders, ±1.5-2.2% is more than adequate. The variability is below the day-to-day variability in your own fitness (3-5%). But for athletes who care about precision training (e.g., FTP testing, structured periodization), the tighter accuracy of competitors matters.

Battery life: a major plus

300+ hours on a single user-replaceable CR2450 coin cell. For comparison: Assioma PRO MX and Rally RK200 deliver 120 hours via rechargeable (worse for travelers without power). The 300-hour battery is the PM-Dual's biggest differentiator.

The verdict

The Power2Max PM-Dual is a solid mid-range power meter with one key advantage (battery life) and one disadvantage (slightly worse accuracy than competitors). For riders who travel, commute in all weather, or simply forget to charge devices, the CR2450 convenience is worth $300 more in cost over a rechargeable. For sprint-focused athletes or precision trainers, the tighter accuracy of Favero or Garmin is worth the premium.