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Stages Shimano Ultegra R8100 Power Meter

Josh Matthew May 23, 2024
4.50 out of 5 based on 2 customer ratings
(2 customer reviews)

Original price was: $449.99.Current price is: $382.99.

Save: 15%

Stages Cycling performance on Shimano’s best-selling R8100 crank arm

Please see our note below on Stages Rider Support

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Stages Shimano Ultegra R8100 Power Meter

The Stages Shimano Ultegra R8100 Power Meter combines Shimano’s award-winning Ultegra groupset with Stages Cycling’s proven performance and dependability. The result is an accurate, lightweight, durable power that comes ready to ride on a Shimano R8100 crank arm. Compatible with all Shimano Hollowtech II road cranks, the Stages Ultegra R8100 runs off of a CR2032 battery and features 200 hours of battery life.

In addition, the power meter is extremely lightweight – adding only 15 grams to the weight of the crank arm. All Stages power meters are compatible with both ANT+ and Bluetooth SMART devices, which means you can use your favorite bicycle computer as well as a smartphone or tablet.

The Stages R8100 power meter (Generation 3) features radio antennas that are 6x more powerful than the previous version. This means better compatibility with both bike computers and watches. The new versions also feature improved accuracy (+/- 1.5%) and have an LED indicator light on the housing for improved ease of use.


~Stages Rider Support~

It has come to our attention that Stages no longer has the resources to offer product support or warranty services. That said, if purchasing a Stages product, we do our best to answer product or troubleshooting-related questions. Knowing this, please shop Stages products assuming there may not be any future manufacturer support. Please note that Power Meter City cannot facilitate any warranty services.


Key Product Details


This power meter is compatible with Shimano R8100 cranksets. It can also be installed on other Shimano road cranksets, as long as they use Shimano’s Hollowtech II interface. See Compatibility tab for more information.

Power Measurement:

This Stages power meter measures left leg power and doubles the value to account for both legs (assumes both legs are generating the same force).

Key Features:

Affordable, accurate to within +/- 1.5%, lightweight at only 15 grams of added weight, 200+ hours of battery life, CR2032 user-replaceable battery, ANT+ and Bluetooth compatible, easy to install. See Specs tab for more information.

Advice From Our Staff:

Stages left side crank arms are some of our best-selling units. They work with most Shimano cranksets, are affordable and easy to install. The one consideration is they only measure left leg power compared to some other power meters that measure power from both legs (those versions usually cost more however).


Options For This Power Meter

Crank arm lengths: This power meter is available in the following crank arm lengths:

  • 160 mm | 165 mm | 170 mm | 172.5 mm | 175 mm


Other Versions to Consider

Dual-Sided R8100 Crankset: We also sell the Stages Shimano Ultegra R8100 Dual-Sided Power Meter which is a complete crankset. It is more expensive, however it measures power from both legs.

Right-Side R8100 Crank Arm: If you currently have a Stages Shimano R8100 left side crank arm, we have the Stages Shimano Ultegra R8100 Right Side Power Meter which allows you to upgrade to a dual-sided power meter. Or, some bike frames cannot fit a left side crank arm-based power meter due to clearance issues with the chainstay. In these situations, the Stages right side power meter is a perfect solution.


Crankset: The Stages Shimano Ultegra R8100 Power Meter is compatible with Shimano R8100 cranksets.

Please note, the power meter can also be installed on other Shimano road cranksets, as long as they use Shimano's Hollowtech II interface. These cranksets can easily be identified by the two opposing pinch bolts that are used to secure the left side crank arm. Please see the image below and contact us if you have any questions on compatibility.Shimano Hollowtech II Left Crank Arm

Check Frame Clearance: Crank-arm based power meters like this one attach a sensor on the inside of the left crank arm. On some bikes, there is not enough room between the left crank arm and the chainstay for the sensor to clear the frame. Therefore, you should make sure you have at least 10 mm of clearance between the left crank arm and the chainstay - and that you don't have a bottom bracket mounted rear brake (used on some aero and TT bikes). The important area to measure is right in the middle of the crank arm. Please refer to the image below.

If you find that you have around 7-9 mm of clearance, what many people will do is simply install a 1 or 2 mm bottom bracket spacer (between the left crank arm and the frame), which will give them the clearance they need.

The clearance between the frame and left side power meter crank arm

Stages Ultegra R8100 Power Meter Specs

NameStages Shimano Ultegra R8100
Bike TypeRoad
Location of Power MeasurementCrank Arm
Left or Both Legs MeasuredLeft only
Independent Left/Right MeasurementNo
Crank Arm MaterialAluminum
Communication ProtocolANT+ and Bluetooth SMART
Claimed Accuracy+/- 1.5%
Automatic Temp. CompensationYes
Weight15 grams (added weight)
Battery TypeCR2032 coin cell
Battery Life200+ hours
Method of Cadence MeasurementAccelerometer
Warranty1 year

In the Box

  • Stages Power Meter
  • 2032 coin cell battery
  • Quick Start guide

Tools Needed for Installation

You will need the following tools for installation of this product. You can purchase many of these commonly used tools in our store.

  • Shimano Crank Arm Cap Tool
  • 5 mm Allen key

Common Questions and Answers

Question: How do I determine what length my current cranks are so I can make sure I get the same size?

  • Your crank arm length should be printed or stamped on the inside of the left crank arm, usually near the pedal end.

End of crank arm showing crank arm length

2 reviews for Stages Shimano Ultegra R8100 Power Meter
  1. Arturo (verified owner)

    So far the Ultegra 8100 is working just fine! Had to adjust it a few times to engage it with my Garmin but its working great so far!
    Thanks again with the speedy delivery guys!

    • Power Meter City

      Looks like you are enjoying them, Arturo! Great choice BTW! Please let us know if there is anything else we can do!

  2. Rob

    I decided to skip Shimano’s R9200 power meter for my 12-speed build and instead use this Stages left-side unit. My previous power meter was an R9100p and while it’s a great unit, I didn’t notice much benefit from the dual sided power because of my balanced L/R ratio. The Stages power meter is way less expensive and it connected to my Garmin 1030 without any trouble at all. If the runtime is 300hrs as claimed I will be perfectly happy.

    • Power Meter City

      Good choice, Rob! Thank you for this amazing review, we hope you will continue to enjoy your new Stages power meter and we are here if there is anything else we can help you with! Ride safe!

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