Skip to main content
Banner image for our Stages vs 4iiii Crank Arm Power Meter article

Stages vs 4iiii Crank Arm Power Meter?

Stages Cycling shook up the power meter market in 2012 with the introduction of their left-side crank arm power meter. Unlike previous power meters at the time, the Stages power meter measured left leg power only and meant you simply swapped out your current crank arm for a new, power equipped one. It was also the first power meter to use both ANT+ and Bluetooth SMART protocols. While Stages was first to the party with this type of power meter, 4iiii Innovations quickly followed suit, producing their own version of a left-side crank arm power meter. While the Stages and 4iiii power meters share many similarities…they are not without their differences. So we thought it would be helpful if we conducted a Stages vs 4iiii comparison by putting these two power meters head-to-head.

Banner image for our Stages vs 4iiii Crank Arm Power Meter article


Stages vs 4iiii Crank Arm Power Meter?

Left-side crank arm power meters have become one of the most popular power meters out. In a nutshell, here’s why:

  • Affordable – Since you are just buying the left-side crank arm (instead of an entire crankset, new set of pedals, etc.), they are one of the more affordable power meters you can buy. In fact, 4iiii’s PRECISION is the most affordable direct force power meter available with a price of $399.99 for their Shimano 105 5800 unit.
  • Easy to install – This design allows for easy installation and swapping of the power meter between bikes. The power meter can be installed or moved between bikes in about 5-10 minutes.
  • Light – They are extremely light. The Stages and 4iiii PRECISION adds 20 grams and 9 grams, respectively, to your bike. Almost nothing.

It is important to note however that one consideration with a left-side crank arm power meter is just that…it’s left-side only. This means it takes your left leg power and doubles it to approximate total power. This is fine for some folks, and maybe not for others.

So if you’re okay with a left-only power meter and like things like affordability, ease of installation and lightweight (who doesn’t!), than a Stages or 4iiii might be right for you. Below, we briefly summarize these two companies and put the power meters head-to-head across several key considerations you’ll likely want to consider.


Overview of the Stages Cycling and 4iiii PRECISION Crank Arm Power Meter

Stages Cycling

Stages Cycling got their start in the indoor fitness market, manufacturing power-equipped indoor cycling bikes. Starting in 2010, they began work on an outdoor version of their power meter and by 2012, they were producing what is now referred to as the Stages Cycling Power Meter.

The Stages power meter was the first power meter to use both ANT+ and Bluetooth SMART protocols, as well as Active Temperature Compensation, which works to keep the power meter accurate regardless of temperature changes.

Stages now produces a range of power meters for Shimano, Campagnolo, FSA, Cannondale, SRAM and Race Face; including carbon crank arms. Prices range from $529 to $949.

Image of Stages Cycling Shimano Ultegra 6800 Power Meter

Image of 4iiii PRECISION Shimano 105 5800 Power Meter


4iiii Innovations, maker of the PRECISION, is based in Alberta Canada and develops a range of sports performance technologies. The company entered the power meter market in late-2014, unveiling the PRECISION, the world’s lightest power meter.

Like the Stages, the 4iiii PRECISION is a left-side crank arm power meter that takes your left leg power and doubles it to approximate total power. 4iiii features ANT+ and Bluetooth SMART, claims an accuracy of +/- 1.0% and runs off of a CR2032 battery. Unlike the Stages however, the PRECISION is compatible with Shimano cranksets only.

Head-to-Head Comparison



Since both of these power meters are left-side crank arms, they both install the same way. You simply remove your current, left-side crank arm and replace it with your new, power-equipped version. Installation typically takes about 5-10 minutes for most models. Some models, such as the Stages Carbon power meters, require you to change out your spindle as well, and this adds an extra step to the process. But it is still a relatively basic process and can be performed at home in your garage as long you have access to some Allen keys and a torque wrench.


Weight4iiii Innovations logo

The 4iiii PRECISION takes the win here as it is the lightest power meter you can buy, adding a mere 9 grams to your bike! But we have to admit, this is splitting hairs a bit. The Stages power meter only adds 20 grams – which is still almost nothing. Therefore, since the weight is negligible for both of these power meters, you could really call it a tie.


Battery Type


Both power meters run off a 2032 coin cell battery. The 2032 is popular among power meters. They’re cheap (you can pick up a six-pack for about $4 or $5), have decent battery life and are simple to install.


Battery LifeStages Cycling logo

Because both power meters run off the same 2032 coin cell battery, you would expect battery life to be pretty similar. When in fact, Stages claims a battery life of about 200 hours, compared to 100 for the 4iiii. Considering the CR2032 battery is cheap and is easily changed, we don’t consider this a big win…but a win none-the-less.


Communication Protocol


Both the 4iiii PRECISION and Stages Cycling power meters transmit via both the ANT+ and Bluetooth SMART wireless protocols. This makes the power meters compatible with either your favorite head unit or smart phone.




We are going to call this one a tie as well. The 4iiii PRECISION claims an accuracy of +/- 1.0%, whereas Stages claims an accuracy of +/- 2.0%. However, the 1.0% difference we are talking about here is minimal. In addition, it’s really hard to validate this differential. Numerous third party tests have shown both power meters to track other, popular power meter models closely. Is it possible that the 4iiii is slightly more accurate…perhaps, but in the grand scheme of things, we don’t think this should be a deciding factor.




Both of these power meters require the user to perform a calibration (technically called a zero-offset) procedure before every ride. The process of zero-offsetting is quick and easy.




Both the 4iiii and Stages are warranted to be free from any manufacturing defects for 1 year. In addition, customer support is top notch for both of these brands.


Crankset CompatibilityStages Cycling logo

Stages Cycling takes the win here. Stages makes crank arms that are compatible with Shimano, Campagnolo, FSA, Cannondale, SRAM and Race Face drive trains. They offer carbon arms as well. 4iiii on the other hand, only offers crank arms for Shimano. Crankset compatibility is the biggest difference between these two brands.


Cost4iiii Innovations logo

Assuming you are in the market for a Shimano crank arm, the 4iiii PRECISION is priced below the Stages models. Here are how the prices compare. Note that if you are shopping for a different brand (Campagnolo, FSA, etc.), then a cost comparison is not applicable since 4iiii only sells Shimano crank arms. In this case, your only choice is Stages.

105 5800

  • 4iiii – $399.99
  • Stages – $529.99

Ultegra 6800

  • 4iiii – $499.99
  • Stages – $579.99


  • 4iiii – $499.99
  • Stages – $649.99 (currently on sale for $449.99)

XT M8000

  • 4iiii – $499.99
  • Stages – $579.99

XTR M9000

  • 4iiii – $599.99
  • Stages – $649.99


Summary: Stages vs 4iiii

As you can see, and as we mentioned at the outset, these two power meters share many similarities (installation, battery, communication protocol, calibration, warranty). But there are some differences as well. Most notably price (4iiii is lower – for Shimano) and crankset compatibility (Stages is compatible across dozens of cranksets).

We’ve personally owned and trained on both of these power meters and they’ve been great. It really comes down to what’s important to you – and quite frankly, what equipment you’re currently running. If you have a Shimano crankset and want to save some money, the 4iiii PRECISION is probably a great choice. On the other hand, if you have a SRAM or FSA crankset for example, you’re looking at Stages. We are pretty confident that regardless of your choice, you’ll enjoy it and will be a stronger cyclist for training with power.

Josh Matthew

Related News

Stages Generation 3 banner image

Stages Generation 3 Power Meters

Stages Generation 3 Power Meters We're excited to announce the launch of the Stages Generation...

Banner image of the 4iiii PRECISION Power meter, which is the lightest power meter you can buy

Lightest Power Meter

We have said before that weight shouldn't be your main criteria when choosing a power...

Leave a reply

Your email address will not be published. Required fields are marked *

Shopping Cart