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Stages Cycling
Shimano 105 Gen 3 L Power Meter Crank Arm

4.8 out of 5 stars
5 Reviews



Why We Like The Shimano 105 Gen 3 L Power Meter Crank Arm

Now that you're looking to take your riding to the next level, you want to add a power meter to your setup to maximize your training but you have a couple of reservations. You don't want to waste your existing crankset, and you don’t want it to cost a fortune. Thanks to Stages Cycling and its Shimano 105 L Gen 3 Power Meter Crank Arm, you can simply add on a non-driveside crankarm letting you maintain the aesthetic and precision shifting rings while adding accurate power measurement to your steed.

This non-drive side crank arm is exactly the same as the standard 105 crank arm you currently have with a Stages power meter affixed to its inner surface. Tucked inside this little pod, strain gauges and an updated Gen 3 accelerometer measure torsional force and rotation speed to calculate power and deliver this data to your head unit via updated Bluetooth LE or ANT+ radios with a 6-time improvement in transmission strength. These measurements come with a claimed accuracy of +/- 1.5%, which is very much in-line with the best power meters on the market.


  • A 105 left crankarm with power measuring capability
  • Measures power with an impressive +/-1.5% accuracy
  • Active Temperature Compensation accommodates changing temperatures
  • Updated accelerator measures cadence
  • Improved wireless communication boosts the signal strength
  • Pairs with Stages Power App for firmware updates and zero resets
  • 200+ hour battery life with easily-changeable CR2032 coin-cell battery
  • Stages Cycling brings power data into an affordable price range
  • Item #SGCA03X
Shimano Hollowtech II road drivetrains
Accuracy (+/-)
Operating Time
200+ hours
left crank arm
Claimed Weight
6.9oz (196g)
Manufacturer Warranty
1 year

Overall Rating

5 based on 5 ratings

Review Summary

1 Stars - 0 reviews
2 Stars - 0 reviews
3 Stars - 0 reviews
4 Stars - 1 reviews
5 Stars - 4 reviews

Fits True To Size

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Runs smallTrue to sizeRuns large

What do you think about this product?


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5 out of 5 stars

May 23, 2022

Alternative to SRM

I've put it through the wringer

I own three SRM's currently but needed something for my bad weather bike. I know SRM's are sealed really well but I wanted to be careful. This Stages unit is probably 99% as accurate and the cost was so low I don't care if it doesn't last more than 1-2 years (although I have no reason to think it won't but I'd rather ruin a $300 power meter than a $4000 (yes SRM's used to cost that much, insane)) power meter. Anyway, replaceable battery is another plus over my SRM's as I have to send those back to SRM for battery changes. Kind of archaic to be honest but that's just what older tech was. So far reliable and precise.

Matthew S
4 out of 5 stars

January 14, 2022

Works great, but fairly useless

I've put it through the wringer

Easy to install, easy to connect, just seems to work. I first put it on my bike which was installed on a Tacx Neo trainer and observed pretty big power differences between the crank arm and the trainer. After doing more rides and testing I believe most the differences come from my left foot / right foot imbalance. Of course if you've never had a power meter that tells you your left/right power you wouldn't know this. Pretty much immediately had buyers remorse after this and felt like I should have got a different style power meter that does measure both sides. At the end of the day the single crank arm power meter is cute and cheap but pretty much useless to help you measure and improve performance. I'd give the crank arm a five star rating because it does exactly what it says it does, installs really easily and I had zero issues with syncing it up to my watch and computers. With that said I'd highly recommend researching power meters and determining what your personal needs are and if this will work for them. In hindsight I'd save up your money and get power pedals.

Michael C

Originally reviewed on

5 out of 5 stars

January 10, 2022

First power meter

I've put it through the wringer

Finally decided to get a more accurate power meter, from using calculated power. It works on all the software Im using, wahoo and trainer road. Used it on a trainer and on the road. Easy to install and calibrate, just awesome!

ronald P

Originally reviewed on

5 out of 5 stars

January 30, 2021

Perfect product

I've used it several times

After trying another brand that wouldn't calibrate and had instructions that included a troubleshooting guide that had way too many pages, I bought this one. Took me less time to install, calibrate and test than it took me to read the instructions on the other one. It installs easily, calibrates in seconds, and works consistently and steadily. Now I can see what changes my power output and how much different conditions require almost instantly. Lots of useful information to accelerate improvement! I wish there was a similar product for the SRAM Eagle drivetrain so I could put one on my mtn bike.

Don D

Originally reviewed on

5 out of 5 stars

November 26, 2020

Change the way you ride

I've used it several times
Size Bought:
5' 9"

Excellent product, simple install, and easy to configure with your smartphone. Changed the way I ride almost immediately. If you are looking to get faster and ride longer and have never had a power meter before (like me) this one is the cheapest way to do it. I used to watch my speed to judge my effort in my workouts but watching my power output is a huge eyeopener.