4iiii and Stages are the two most popular left-sided power meter brands today.
4iiii has two models available; the 4iiii Precision and 4iiii Precision 3, while Stages have one model; the Stages Power Left (Gen 3).
Both 4iiii and Stages power meters look very similar from the outside, but that’s where the similarities end.
In this article, we’ll compare the 4iiii Precision, 4iiii Precision 3, and Stages Power Left.
Key takeaways
- Crankset compatibility. Stages have wider compatibility across Shimano, Cannondale, and Campagnolo crankarms, while 4iiii is only limited to Shimano.
- Frame compatibility. 4iiii Precision 3 is the slimmest at 5.5mm, making it compatible with more framesets.
- Battery life. 4iiii Precision 3 has the longest battery life at 800 hours.
- Warranty. 4iiii has the better warranty at 3 years.
- Price. Both 4iiii Precision 3 and Stages Power Left are similarly priced, with the older 4iiii Precision priced around $40 lower.
Ease of installation
Both 4iiii and Stages are installed the same way. Remove the current left-sided crank arm, and replace it with the power meter version.
The power meter unit height;
- 4iiii Precision 3 : 5.5mm
- 4iiii Precision : 8mm
- Stages Power Left : 7.5mm
The power meter units are small and will clear most frames. However, always check if there is enough clearance between the left crank arm and chainstay. 4iiii has a printable Clearance Check document for potential buyers.
Crankset compatibility
This is the area where Stages have a major advantage over the 4iiii.
- Stages have wider compatibility with Shimano (105, Ultegra, Dura Ace, GRX), Cannondale and Campagnolo Super Record (11s and 12s), and Record (11s) cranksets.
- 4iiii is only compatible with Shimano (105, Ultegra, Dura Ace, GRX) cranksets.
| Crankset | 4iiii Precision 3 | 4iiii Precision | Stages Power Left |
|---|---|---|---|
| Shimano 105 R7000 | Yes | Yes | Yes |
| Shimano Ultegra R8000 | Yes | Yes | Yes |
| Shimano Ultegra R8100 | Yes | ||
| Shimano Dura Ace R9000 | Yes | ||
| Shimano Dura Ace R9100 | Yes | Yes | Yes |
| Shimano Dura Ace R9200 | Yes | ||
| Shimano GRX810 | Yes | Yes | Yes |
| Shimano XT M8000 | Yes | ||
| Shimano XT M8100 | Yes | Yes | Yes |
| Shimano XTR M9000 | Yes | ||
| Shimano XTR M9100 | Yes | Yes | Yes |
| Campagnolo Super Record 12s | Yes | ||
| Campagnolo Record 12s | Yes | ||
| Campagnolo Super Record 11s | Yes | ||
| Cannondale SI | Yes | ||
| FSA SL-K | Yes |
Data accuracy
Both 4iiii and Stages have some of the best accuracies in power meters. The 4iiii Precision and Precision 3 are accurate up to +/-1% and Stages at +/-1.5%.
For comparison, the Power2max NG (±1%) and NGEco (±2%), Sigeyi (±1.5%), SRAM AXS (±1.5%) and SRM (±2%).
The 4iiii has a maximum power detection of 4000W, and Stages at 5000W. Many cyclists rarely go above 2000W, so this is not an important consideration.
| 4iiii Precision 3 | 4iiii Precision | Stages Power Left | |
|---|---|---|---|
| Accuracy | ±1% | ±1% | ±1.5% |
| Max. power | 4,000W | 4,000W | 5,000W |
Battery
Both 4iiii and Stages use the coin CR2032 battery. It’s cheap and easily replaceable without any tools. Just turn the battery cap anticlockwise to remove it.
4iiii Precision 3 has the longest battery life at 800 hours. The older 4iiii Precision has the shortest battery life at 100 hours, followed by Stages Power Left (150 hours).
| 4iiii Precision 3 | 4iiii Precision | Stages Power Left | |
|---|---|---|---|
| Battery type | CR2032 | CR2032 | CR2032 |
| Battery life | 800 hours | 100 hours | 150 – 200 hours |
Wireless communication
ANT+ and Bluetooth Low Energy (BLE) are used to communicate with bike computers.
The Stages and 4iiii Precision 3 have an improved radio antenna design that solves the loss of signal issue faced in the previous versions.
Cadence sensor
Both 4iiii and Stages have a built-in cadence sensor. Each model has a slightly different cadence detection range;
- 4iiii Precision (30 – 150 RPM)
- 4iiii Precision 3 (30 – 170 RPM)
- Stages Power Left (10 – 220 RPM)
Many cyclists rarely go above 130 RPM, so the cadence range is not an important consideration.
Warranty period
4iiii has a better warranty cover at 3 years vs Stages’ one-year warranty.
Pricing
Both Stages and 4iiii Precision 3 are competitively priced relative to each other. The 4iiii Precision 3 costs $10 more than the Stages for a similar model.
As the 4iiii Precision is an older model, it’s about $40 cheaper than the Stages.
The table below shows the recommended retail prices for all models.
| Crankset model | Precision 3 | 4iiii Precision | Stages Power Left |
|---|---|---|---|
| Crankset model | Precision 3 | Precision | Stages Power L |
| Shimano 105 R7000 | $335 | $285 | $325 Performance Bike |
| Shimano Ultegra R8000 | $385 Performance Bike | $335 | $375 Performance Bike |
| Shimano Ultegra R8100 | $435 Competitive Cyclist | ||
| Shimano Dura Ace R9000 | $480 | ||
| Shimano Dura Ace R9100 | $490 | $440 | $480 Performance Bike |
| Shimano Dura Ace R9200 | $500 Competitive Cyclist | ||
| Shimano GRX810 | $385 | $335 | $375 Competitive Cyclist |
| Shimano XT M8000 | $375 | ||
| Shimano XT M8100 | $385 | $335 | $375 |
| Shimano XTR M9000 | $570 | ||
| Shimano XTR M9100 | $515 | $465 | $570 Competitive Cyclist |
| Campagnolo Super Record 12s | $900 Competitive Cyclist | ||
| Campagnolo Record 12s | $750 | ||
| Campagnolo Super Record 11s | $850 | ||
| Cannondale SI | $375 Performance Bike | ||
| FSA SL-K | $540 |
Alex Lee is the founder and editor-at-large of Mr. Mamil. Coming from a professional engineering background, he breaks down technical cycling nuances into an easy-to-understand and digestible format here.
He has been riding road bikes actively for the past 12 years and started racing competitively in the senior category during the summer recently.