Power meter selection has gotten complicated with all the pedal, crank, and hub options flying around. As someone who has tested power meters for years across road, gravel, and mountain bikes, I learned everything there is to know about what actually matters when choosing one. Today, I will share it all with you.
Probably should have led with this section, honestly: power meters have transformed cycling training by providing objective measurement of your effort. But with options ranging from $300 to $1,500+, understanding the differences helps you choose the right tool without overspending.
Why Power Actually Matters
Power measurement offers real advantages over heart rate and perceived effort:
- Instant feedback: Power responds immediately to effort changes; heart rate lags by 20-30 seconds
- Unaffected by external factors: Heart rate varies with caffeine, sleep, temperature, and stress; power doesn’t
- Precise pacing: Know exactly how hard you’re working, preventing early burnout on climbs or time trials
- Training quantification: Track training load and progress objectively over weeks and months
How Power Meters Work
All power meters use strain gauges—small sensors measuring how much force deforms a component. When you pedal, the crank arm, pedal spindle, or hub flexes microscopically. Strain gauges detect this deflection and, combined with cadence measurement, calculate power (watts = torque × angular velocity).
That’s what makes placement location endearing to us gear nerds—where the strain gauges sit affects accuracy, data collected, and price.
Pedal-Based Power Meters
Pedal power meters replace your existing pedals with units containing strain gauges and electronics.
Why I Like Them
- Easy installation: Swap pedals between bikes in minutes
- Transferable: Use on any bike with compatible threads
- Left/right balance: Dual-sided options measure each leg independently
- No interference with components: Works with any crankset
The Downsides
- Pedal system lock-in: Must use the power meter’s pedal type (SPD-SL, Look, Speedplay, or flat)
- Ground clearance: Some models sit lower than standard pedals
- Vulnerability: Pedals face impact from drops and debris
- Weight: Generally heavier than crank-based options
Top Pedal Options
Garmin Rally: Available in SPD-SL (RS), Look (RK), and SPD (XC) versions. Single-sided starts at $549; dual-sided at $1,099. Accurate and reliable with excellent battery life.
Favero Assioma: Look-compatible pedals offering exceptional value. Duo (dual-sided) at $695 delivers accuracy matching $1,000+ competitors. The Assioma Pro MX supports SPD cleats for gravel and mountain biking.
SRM X-Power: Premium option from the original power meter company. $899 for single-sided. Known for durability and accuracy.
Crank-Based Power Meters
These mount strain gauges in the crank arm or spider (the piece connecting chainrings to the crank).
Crank Arm Systems
Strain gauges embedded in the left (single-sided) or both (dual-sided) crank arms measure power as you pedal.
Advantages:
- Clean look with concealed electronics
- Protected position away from impacts
- Compatible with any pedal system
Disadvantages:
- Single-sided systems assume equal left/right power (not always accurate)
- Must match crankset brand/model for replacement arms
- Transfer between bikes requires removing cranks
Spider-Based Systems
The spider sits between the crank and chainrings, measuring total power directly.
Advantages:
- Measures actual total power (not doubled single-leg)
- Typically very accurate and stable
- Works with any pedals
Disadvantages:
- Must match bottom bracket and crank specifications
- Often requires professional installation
- Generally more expensive than arm-based options
Top Crank-Based Options
Shimano Power Meter: Integrated into Dura-Ace and Ultegra cranksets. Dual-sided measurement with seamless integration. R9200-P crankset starts at $1,400.
SRAM AXS Power Meter: Spider-based system integrated into Force and Red cranksets. Works with existing AXS cranks. Spider kit starts at $420.
Stages Power: Popular single-sided option starting at $299. Dual-sided available from $579. Wide crankset compatibility including Shimano, SRAM, FSA, and Campagnolo.
Quarq DZero: Spider-based system known for accuracy and durability. Works with various SRAM and generic cranks. $899 for the spider.
Power2Max: Spider-based with excellent value. NG and NGeco models start at $499 with +/-1% accuracy claims.
Hub-Based Power Meters
These measure power at the rear wheel hub, capturing your total output after drivetrain losses.
The PowerTap Legacy
PowerTap popularized hub-based power but the company has wound down. Used PowerTaps remain available and accurate, but support is limited. New options from 4iiii and others are emerging.
Advantages
- Measures actual power delivered to the wheel
- Unaffected by pedal or crank changes
- Often very durable
Disadvantages
- Locked to one wheelset
- Cannot transfer between bikes easily
- Fewer current options available
Single vs Dual-Sided
Single-sided meters measure one leg and double the value. This works if your legs are balanced, but many riders aren’t perfectly 50/50. Dual-sided meters measure both legs independently, giving true total power and left/right balance data.
For most recreational riders, single-sided is fine. Serious racers and those with known imbalances benefit from dual-sided accuracy.
What I Recommend
Budget pick: Stages Power single-sided at $299. Accurate, reliable, widely compatible.
Best value: Favero Assioma Duo at $695. Dual-sided accuracy at single-sided competitor pricing. Easy transfer between bikes.
Premium pick: Garmin Rally or SRAM AXS spider if you’re already in that ecosystem. Seamless integration and excellent accuracy.
Focus on accuracy, compatibility with your bikes and pedals, and ease of transfer if you ride multiple bikes. The differences between quality power meters are smaller than marketing suggests—any reputable option will transform your training.
