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INPEAK POWERCRANK-E Shimano GRX FC-RX810 / RX820 – rechargeable power meter
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Shimano GRX FC-RX810 / FC-RX820 left crank arm with integrated INPEAK POWERCRANK-E power meter. Left-side measurement with ±2% claimed accuracy, rechargeable battery with up to 90 hours of runtime, ANT+ / Bluetooth and IP67 protection. A particularly relevant solution for adding power measurement to a GRX gravel bike without replacing the crankset, chainrings or bottom bracket.
Arm length
INPEAK · POWERCRANK-E · GRAVEL
Shimano GRX Gravel Power Meter RX810 / RX820: INPEAK POWERCRANK-E
Looking for a Shimano GRX gravel power meter without replacing your entire crankset? The INPEAK POWERCRANK-E is built into a genuine Shimano GRX left crank arm and measures power and cadence. This rechargeable version is designed for Shimano GRX FC-RX810 (11-speed) and FC-RX820 (12-speed) cranksets, with ANT+ and Bluetooth Low Energy connectivity.
Add power-based training to your gravel bike, pace long-distance gravel events or control your effort on climbs while keeping your existing chainrings, spindle and bottom bracket when the setup is compatible.
MEASUREMENT
Left-side only
BATTERY LIFE
Up to 90 hours
ACCURACY
Claimed ±2%
CONNECTIVITY
ANT+ + Bluetooth
Which power meter should you choose for a Shimano GRX gravel bike?
If you are happy with your current Shimano GRX RX810 or RX820 crankset, this INPEAK left crank arm power meter is a straightforward way to get power data without buying a complete new crankset. The sensor comes factory-integrated into a new crank arm; you do not need to send your existing arm away for modification.
Before ordering: check the exact crankset model (not just the derailleur model), crank length and clearance between the sensor and frame. Check compatibility · Read the FAQ.
Velo-Perso's view
Gravel riding creates demands that are different from road cycling. On rough ground, some of your effort goes into controlling and stabilising the bike: steering, changes in body position, traction losses and impacts all require energy that does not necessarily appear as extra watts at the crankset. At a similar perceived effort, your recorded gravel power curve can therefore be lower than your road power curve.
In this context, measuring from the left crank arm alone is not necessarily a major limitation. The main benefit is being able to compare gravel rides with other gravel rides, pace your efforts and track progress against a consistent reference, rather than expecting road and gravel data to match watt for watt.
With straightforward installation, a rechargeable internal battery and a genuine Shimano GRX crank arm, the INPEAK POWERCRANK-E GRX is, in our view, a particularly sensible and competitive gravel power meter.
Why fit a power meter to a Shimano GRX gravel bike?
Shimano GRX cranksets are already designed for gravel riding. If your current crank length, gearing and bottom bracket suit you, there is little reason to replace the whole crankset just to start training with power.
INPEAK takes a simple approach: replace only the left crank arm with a genuine Shimano GRX arm fitted with its POWERCRANK-E sensor. The right crank arm, chainrings, spindle and bottom bracket can remain in place on a compatible setup. You gain a gravel crankset with a power meter while preserving the shifting and geometry you already know.
Better pacing
Use smoothed power to avoid starting too hard, pace long climbs and control your effort as the surface changes.
Use smoothed power to avoid starting too hard, pace long climbs and control your effort as the surface changes.
Track your progress
Compare efforts on similar gravel climbs, routes and rides using the same power meter as your reference.
Compare efforts on similar gravel climbs, routes and rides using the same power meter as your reference.
Train with watts
Record power, cadence, training zones and training load without rebuilding your bike.
Record power, cadence, training zones and training load without rebuilding your bike.
→ Read our guide: how to use a cycling power meter at your level
Single-sided power measurement: what does it actually measure?
The POWERCRANK-E SINGLE uses strain gauges to measure force on the left crank arm, then estimates overall power by doubling the left-leg contribution. INPEAK quotes ±2% accuracy for the sensor's measurement.
As with any left-only power meter, a natural left/right leg imbalance can cause the estimated total to differ from your actual combined power. For many gravel riders, repeatability and consistent use of the same power meter over time are more useful than comparing every watt with another measurement system.
There is also a difference between mechanical power transmitted to the crankset and total physical effort on rough terrain. Supporting and stabilising your bike requires energy too. A dual-sided crankset can measure both legs more completely, but it cannot measure upper-body work.
Shimano GRX RX810 and RX820 power meter compatibility
This INPEAK gravel power meter version is specified for Shimano GRX FC-RX810 (11-speed generation) and FC-RX820 (12-speed generation) cranksets. Having a 1x or 2x gravel drivetrain does not, by itself, determine compatibility: the exact crankset model, crank length and available frame clearance matter.
A bicycle fitted with an RX820 rear derailleur may use a different crankset, such as an FC-RX610. Do not choose a power meter based only on your groupset or rear derailleur name. Compatibility with FC-RX600, FC-RX610 and FC-RX400 is not confirmed for this particular product listing. Contact us before ordering if your bike has one of those cranksets.
Check before ordering: choose the same crank length as your existing crank arm (170, 172.5 or 175 mm, depending on the available variant). Measure the space between the sensor module on the inside of the left crank arm and the left chainstay: at least 8 mm of clearance is recommended. This is especially important on gravel frames with wide chainstays.
Not sure which Shimano GRX crankset you have, or whether the module will clear your frame? Velo-Perso can help verify your setup before you buy.
Rechargeable battery: up to 90 hours of riding
POWERCRANK-E uses an integrated 110 mAh rechargeable Li-Po battery. INPEAK states up to 90 hours of operation and approximately two hours for a full charge. Charging is through the supplied magnetic USB cable.
Low-battery alerts, automatic sleep and wake-up modes make day-to-day use straightforward. You can recharge the sensor rather than regularly opening a coin-cell battery compartment.
Technical specifications
| Measurement type | Single-sided, left crank arm |
| Compatible cranksets | Shimano GRX FC-RX810 / FC-RX820 |
| Claimed sensor accuracy | ±2% |
| Power measurement range | 20–2,000 W |
| Cadence measurement range | 20–200 rpm |
| Additional sensor weight | Approx. 10 g on the crank arm |
| Water and dust resistance | IP67 |
| Operating temperature | -5°C to +50°C |
| Temperature compensation | Automatic |
| Internal sensors | Gyroscope and accelerometer |
| Available data | Power, cadence, Torque Effectiveness, Pedal Smoothness |
| Wireless connection | ANT+ and Bluetooth Low Energy |
| Battery | 110 mAh rechargeable Li-Po |
| Claimed battery life | Up to 90 hours |
| Full charging time | Approx. 2 hours |
| Charging cable | Magnetic USB cable supplied |
| Firmware updates | INPEAK MANAGER app |
| Zwift-compatible mode | Yes |
Gravel vs road power data: compare like with like
On smooth tarmac, a large share of your physical effort produces measurable power at the crankset. On rough gravel, traction varies and you may have to unweight the saddle or pedals, shift your position or use your upper body more actively. These changes can alter the relationship between how hard a ride feels and how many watts you record.
We therefore recommend building your own gravel power benchmarks: watts on a familiar off-road climb, 5-minute and 20-minute efforts, long-distance pacing, FTP trends and training load throughout the season. These measurements become far more informative when you compare similar efforts over time.
This is where a consistent left-crank power meter earns its place: it delivers a useful, repeatable reference ride after ride, without requiring a complex setup.
→ Compare INPEAK, Rotor and other power meter measurement systems
INPEAK crank arm power meter or a complete power meter crankset?
| INPEAK POWERCRANK-E GRX | Complete power meter crankset | |
|---|---|---|
| Main goal | Add watts to an existing GRX crankset | Upgrade the entire crankset |
| Installation | Replace the left crank arm only | Change crankset and possibly bottom bracket |
| Power measurement | Left-side estimate (left ×2) | Spindle, spider or true dual-sided depending on model |
| Key advantage | Simplicity, lower cost, existing setup retained | Change length, weight, gearing or sensor type |
At Velo-Perso, we see INPEAK and Rotor as complementary options: INPEAK if you want to keep your existing Shimano GRX crankset, or a complete crankset-based power meter when you also want to change crank length, weight, gearing or measurement architecture. Gravel power meter pedals are another option if easy transfer between bicycles is important, provided the pedal and cleat system suits your riding.
European manufacturing and long-term support
INPEAK designs and manufactures its power meters in Poland. For an electronic cycling component intended to last several seasons, European manufacturing can be an advantage for availability, firmware support and after-sales service.
POWERCRANK-E firmware can be updated with the INPEAK MANAGER app. The system also supports zero offset calibration, Scale Factor adjustments and automatic temperature compensation.
Available crank lengths and product references
| Crank length | Manufacturer part number | EAN |
|---|---|---|
| 170 mm | PCV40SHG8270B | 5907465631808 |
| 172.5 mm | PCV40SHG8272B | 5907465631792 |
| 175 mm | PCV40SHG8275B | 5907465631785 |
What's in the box?
- Genuine Shimano GRX left crank arm with integrated INPEAK POWERCRANK-E SINGLE power meter
- 2 m magnetic USB charging cable
- Device information card with PIN for the mobile app
- User manual
- Sticker set
FAQ: gravel power meters and Shimano GRX compatibility
Answers to the most common questions about fitting a power meter to a Shimano GRX gravel bike.
Which power meter is best for a Shimano GRX gravel bike?
If you already have a Shimano GRX FC-RX810 or FC-RX820 crankset, the INPEAK POWERCRANK-E is a simple way to measure power and cadence by replacing only the left crank arm. Your compatible chainrings, spindle and bottom bracket stay in place. If you also want to change crankset components or measure each leg independently, a complete system may be more suitable.
Is this power meter compatible with Shimano GRX RX810 11-speed and RX820 12-speed?
Yes. This version is intended for Shimano GRX FC-RX810 and FC-RX820 cranksets. Check the model of the crankset itself, rather than just the derailleur, and confirm crank length and clearance around the left chainstay.
Will it fit a Shimano GRX RX600, RX610 or RX400 gravel crankset?
This product listing specifies compatibility with FC-RX810 and FC-RX820 cranksets. Do not assume it fits FC-RX600, FC-RX610 or FC-RX400 without checking the exact crank model and frame clearance with us before purchasing.
Can I use this GRX power meter on a 1x or 2x gravel drivetrain?
The sensor measures force at the left crank arm, so having one or two chainrings does not directly affect how it measures power. What matters is the exact FC-RX810 or FC-RX820 crankset configuration and sufficient clearance between the sensor and frame.
Do I need to replace my whole Shimano GRX crankset to install it?
No. INPEAK supplies a new genuine Shimano GRX left crank arm with the POWERCRANK-E sensor fitted. On a compatible bike, you replace that arm and keep the right crank, spindle, chainrings and bottom bracket.
Is a left crank arm power meter accurate enough for gravel riding?
INPEAK claims ±2% sensor measurement accuracy. The displayed total power is estimated from the left leg, so left/right imbalance can create an additional difference from true combined output. For pacing gravel rides and monitoring long-term progress with the same device, this is a useful and practical approach.
Does the INPEAK GRX power meter work with Garmin, Wahoo and Zwift?
POWERCRANK-E broadcasts over ANT+ and Bluetooth Low Energy and includes a Zwift-compatible mode. It can connect to compatible Garmin and Wahoo cycling computers that support the relevant power profile. Check the specifications of your particular head unit or app.
How long does the INPEAK GRX battery last, and is the sensor waterproof?
INPEAK specifies up to 90 hours of battery life, approximately two hours for a full charge with the included magnetic USB cable, and an IP67 dust and water resistance rating. It is suitable for rain and spray, but IP67 should not be interpreted as protection against prolonged submersion.
How do I choose crank length and check frame clearance?
Normally choose the same crank length as your current arm: 170, 172.5 or 175 mm depending on the selected option. Check clearance between the inner face of the left crank arm and the chainstay; at least 8 mm is recommended for the sensor module. Velo-Perso can help confirm fit before ordering.
INPEAK GRX crank arm or gravel power meter pedals: which should I choose?
INPEAK stays integrated with your Shimano GRX crankset and lets you keep your preferred pedals. Power meter pedals may be easier to move between bikes, but you must consider pedal type, cleat compatibility and the conditions in which you ride gravel.
Why buy your INPEAK power meter from Velo-Perso?
Compatibility advice
We look at your actual crankset, crank length, bottom bracket, frame and drivetrain, not just the name of your groupset.
We look at your actual crankset, crank length, bottom bracket, frame and drivetrain, not just the name of your groupset.
Practical product advice
We can explain when a left-arm INPEAK is enough and when a complete crankset or another measurement system makes more sense.
We can explain when a left-arm INPEAK is enough and when a complete crankset or another measurement system makes more sense.
European manufacturer and support
INPEAK designs and manufactures in Poland, helping with technical follow-up and long-term service.
INPEAK designs and manufactures in Poland, helping with technical follow-up and long-term service.
The essentials
If your gravel bike already has a compatible Shimano GRX RX810 or RX820 crankset, POWERCRANK-E adds power data with minimal changes: one rechargeable left crank arm, consistent training data and the GRX setup you already enjoy.
If your gravel bike already has a compatible Shimano GRX RX810 or RX820 crankset, POWERCRANK-E adds power data with minimal changes: one rechargeable left crank arm, consistent training data and the GRX setup you already enjoy.
How to use a power meter · 2026 power meter comparison · Rotor power meters · INPEAK power meters
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