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Stages Cycling Shimano XT M8100/8120 Single Leg Power Meter
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Stages Cycling Shimano XT M8100/8120 Single Leg Power Meter

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Backorder: This item is currently not in stock but is available to purchase today as a backorder. The expected availability date shown above is our best estimate as to when it will be shipped to you, but this date is subject to change based on our receipt of this item from its vendor. Shipping in the continental US is free for all backorder items (for international orders, our customer service team will contact you when the item is available to ship). Your credit card will not be charged until your item ships (Paypal requires payment up front, but you can cancel for full refund). Anytime prior to shipment, your backorder can be cancelled by contacting our customer service team.

Power Isn't Just For Roadies

The Stages Cycling Shimano XT M8100/8120 Single Leg Power Meter measures power and cadence extremely accurately and easily integrates into Shimano XT cranksets.

Stages Power meters are ridden by world and national champions in every discipline of cycling. From weekend warriors to mountain bike Olympians, Stages power meters are for ridden by the best athletes in the world.

The Shimano XT M8100/8120 Single Leg Power Meter uses active temperature compensation as standard equipment. Consistency of measurement is the most important feature of a power meter. Stages Power was the first meter to make temperature compensation an automatic process ensuring accurate readings no matter the environmental conditions.

This power meter also uses individual meter calibration for the most accurate results. Stages power meters are calibrated individually to ensure a plus/minus 1.5% accuracy level. Individual calibration means that you can trust the data produced by Stage's system.


  • Plus/minus 1.5 % accuracy in all conditions
  • Active temperature compensation
  • Accelerometer based cadence measurement
  • Wirelessly upgradable firmware
  • LED indicator displays battery level at startup (with no need to connect to an app) and confirms successful zero reset
  • Updated accelerometer and addition of gyroscope for improved cadence resolution
  • Upgraded BLE and ANT+ radios offer a 6X improvement of data transmission strength
  • Power meter housing: low profile design, with robust door interface
  • Only adds 15g of weight to the base crank arm
  • Battery Life: 200+ hours (coin cell: CR2032) when used as a single-sided meter
  • Power range (Watts): 0 to 5000
  • Cadence range (rpm): 10-220
  • Water resistance rating: IPX7

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.

Battery Life: 200 plus hours 

Cadence range (rpm): 10-220 

Power Range: 0 to 5000 Watts

Water resistance rating: IPX7 

Device Compatibility: ANT Plus, Bluetooth Smart Ready 

Software Compatibility: Stages Link, Training Peaks, Strava, Garmin Training Center and others 


Mfg PartNum: M81L-C 


Mfg PartNum: M81L-E 

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Reviewed 12/20/2021
by Greg D
Tijeras, NM
Overall Rating
Power is key

Works well and appears to give numbers that are reasonably close to what I expect. Probably one of the cheaper options on the market.

But this design may be too dainty for MTB use. On my second ride I smacked the unit hard enough to dislodge the cap. A while later I found the battery had fallen out. Stages sent me a couple of replacement caps. It sounded like this was a fairly common occurrence.

Yes, the strain gauge is mounted on the inside of the crank arm. Rock must have smacked it pretty good.

Tried Rally pedals - heavy and sloppy but true dual sided power and dynamics is interesting, and helped to resolve a pedalling issue. Actually, the data showed I had an issue and after some time with a bike fitter the data showed the issue was gone. Save $1k and simply go see a fitter.

Currently running an Easton cinch bb power meter on my gravel bike. Clean install with nothing hanging out to get hit but may not be ideal for non-desert climates. Don't know how well the cap will keep water out if one needed to ford a stream.

Tried a spider based power meter too but seemed kind of silly to put a spider on a cinch mount and then bolt on a chainring to the spider.

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