There are several power meters that fit Shimano road cranksets, so you have a lot of options. Which power meter is best for you is depends on what Shimano crankset you have (for example, R7000, R8100, etc.) and your budget. Some power meters measure just left leg power, where as others cost a bit more but will measure power from both legs.
In summary, here are the four power meter types you can buy:
- Left Crank Arm Power Meter – affordable, easy to install, measures left leg power only
- Crankset Power Meter (Spider Based) – you replace your Shimano crankset with a new power-equipped crankset. Measures power from both legs. Power is measured at the spider
- Crankset Power Meter (Crank Arm Based) – you replace your Shimano crankset with a new power-equipped crankset. Measures power from both legs. Power is measured on the crank arms
- Power Meter Pedals – power meter pedals can be installed on any crankset, are easy to use and work great. You can buy single-sided or dual-sided versions
Left Crank Arm Power Meter
4iiii and Stages both make left crank arm power meters for Shimano cranksets. With these power meters, you simply swap out your current left crank arm for the new power-equipped version and you are good to go. These versions are affordable and easy to install, however they only measure power from the left leg.
If you have a different version of Shimano crankset (RS510, Tiagra, etc.), in most cases you can still install one of these crank arms. You just need to make sure your crankset uses the Shimano Hollowtech II Standard. These cranksets can be identified by two pinch bolts securing the left crank arm to the spindle. Please contact us if you have questions on this and we would be happy to help.
4iiii Left Crank Arm Power Meters
Stages Left Crank Arm Power Meters
Please note, if you are mixing and matching crank arms (like a Stages R7000 power meter crank arm on a Shimano Tiagra crankset), the color of the crank arms won’t be exactly the same (a cosmetic issue only), but most customers are ok with this.
Please also note, these power meters attach a sensor to 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 for Stages and 4iiii PRECISION 2 power meters and 8 mm of clearance for 4iiii PRECISION 3 power meters. Also, please make sure that you don’t have a bottom bracket mounted rear brake (used on some aero and TT bikes). Please refer to the image below.
Pros: Affordable, easy to install, don’t have to change crankset
Cons: Measures left leg power only
Crankset Power Meter (Spider Based)
These are some of our favorite power meters. You replace your current Shimano crankset for the new power meter version. They measure power from both legs, are accurate and reliable.
This is a new crankset (power meter spider, crank arms and spindle), excluding chainrings. power2max makes wonderful power meters. They measure both left and right leg power, are reasonably priced and are as good as it gets in terms of reliability. If you select the 24MM spindle option, it will fit your current bottom bracket exactly like your Shimano crankset (no need to change bottom brackets). In addition, if you select the Shimano 4-Bolt spider, you can also use your Shimano chainrings on it. This makes it a direct replacement for your Shimano crankset.
The Sigeyi power meter crankset is very similar to the power2max above. It is a spider-based power meter that measures power from both legs and will also serve as a direct replacement for a Shimano road crankset. It is accurate to within +/-1.0%, is lightweight and features a rechargeable battery. The Siegyi is also one of the most affordable power meter cranksets on this page.
This too is a new crankset (power meter spider, crank arms and spindle) and can be purchased with or without chainrings. The INspider measures both left and right leg power, comes in a variety of crank arm lengths and can be set up in a 1X or 2X chainring configuration. This power meter can also be purchased with a 24MM spindle so it will fit your current bottom bracket without any changes. You can use your current Shimano chainrings on it or buy new ROTOR rings.
Like the power2max and ROTOR above, this is spider-based crankset and it’s a wonderful option as well. You would purchase the DFour Power Meter spider as well as Quarq DZero DUB crank arms. At $640, this is quite a bargain for a high-end power meter and carbon crankset. However, unlike the power meters above, with the DFour, you must change your bottom bracket. The DFour power meter requires a SRAM DUB Bottom Bracket. They are relatively inexpensive, but it does make installation a bit more involved.
The DFour is designed for use with Shimano DURA-ACE 9100 chainrings. Shimano Ultegra R8000 chainrings and Shimano 105 R7000 chainrings will also work, however they will not match the shape or color of the power meter as nicely.
Pros: Moderately priced, VERY reliable, measures both legs
Cons: Have to change your crankset
Crankset Power Meter (Crank Arm Based)
In addition to making left side crank arms, 4iiii and Stages also make complete dual-sided cranksets. In addition, Shimano offers a dual-sided crankset with their own power sensors attached. With these power meters, you get a new Shimano crankset with a power sensor attached to the inside of the left and right crank arm. Therefore, they are able to measure power from both legs as well as tell you how much power each leg is producing individually.
4iiii Crankset Power Meters
Stages Crankset Power Meters
Shimano Crankset Power Meters
Please note, these power meters attach a sensor to 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 for Stages and 4iiii PRECISION 2 power meters and 8 mm of clearance for 4iiii PRECISION 3 power meters. Also, please make sure that you don’t have a bottom bracket mounted rear brake (used on some aero and TT bikes). Please refer to the image below.
Pros: Measures both legs, provides independent left/right power
Cons: More expensive
Power Meter Pedals
Power meter pedals can be installed on any crankset. They are reliable, accurate, easy to install and can be moved between bikes. We carry every power meter pedal available including ones from Favero, Garmin, SRM/LOOK and Wahoo. This includes both single- and dual-sided versions as well as pedals for SPD-SL, LOOK Keo and Speedplay cleats.
Pros: Easy to install, works on any bike, can move from bike to bike, don’t have to change crankset