Stages Cycling is known for their left side crank arm power meters. In fact, they were the first company to make a left side crank arm power meter (started in 2012). They are now on the 3rd generation of Stages power meters. They currently make left and ride side crank arms as well as dual-sided cranksets. Stages power meters are lightweight, feature 200 hours of battery life and are compatible with Shimano, Campagnolo, FSA, Cannondale, SRAM and Race Face cranksets.
Installation of Stages left crank arms simply involves removing your current crank arm and installing the Stages in its place. Total installation time is usually less than 5 minutes.
Complete Stages cranksets take a bit more work as you have to swap out your entire crankset. However assuming you have insured compatibility with your bike frame – it’s pretty simple.
Stages power meters are one of the lightest available. The sensors add just 20 grams of weight to the crank arm, the equivalent of about 20 paperclips. If you opt for a dual-sided crankset, you would be adding about 40 grams, as these units have a power sensor on both the left and right crank arms.
Stages left side only crank arms measure left leg power and double the value to calculate total power. This is how all single-sided power meters work. Assuming you do not have a large leg imbalance (in terms of power), this is an accurate way to measure power.
Complete Stages cranksets such as the Shimano Ultegra R8000 and DURA-ACE 9100, measure power from both legs. They are also able to determine independent left/right power.
One of the great things about Stages power meters is their broad selection. They make a left side crank arm for almost any crankset. In addition, with models starting at $299, they are one of the most affordable, ready to ride direct force power meters available. They are also extremely lightweight. These power meters only add about 20 grams of weight to your crankset.
Stages power meters use CR2032 batteries. CR2032 batteries are cheap and easy to find. Battery life is approximately 200 hours, quite good for a battery of this type.
These power meters transmit data via both the ANT+ and Bluetooth SMART wireless protocols. This means they are compatible with any bicycle computer, smart phone or tablet. It also means they can be easily connected with popular training apps such as Zwift.
All Stages power meters are accurate to within +/- 1.5%. This is in-line with most power meters on the market.
Cadence is measured using an accelerometer. An accelerometer is an electronic device that is housed inside the power sensor and measures your pedaling rate.
Stages offers a one-year warranty which covers the product from defects in material and workmanship. We note their warranty support is quite good should you have any issues with your power meter.
How does a Stages power meter work?
Stages Cycling bonds a strain gauge as well as a battery and some electronics onto the inside of the left- and/or right-side crank arm. A strain gauge is a tiny electronic device whose electrical resistance varies depending on how much resistance (strain) is put on them. In the case of a Stages crank arm for example, it measures how much your crank arm is flexing when you ride. The power meter converts this flex into a power or torque reading that is sent wirelessly to your handlebar mounted bike computer where you can view your power in real-time.
Will a Stages power meter fit my bike?
There are two parts to this question. The first is in regards to crankset compatibility. Stages makes a number of different power meters that fit on different cranks. You must be sure you purchase the correct power meter based on what crankset you have on your bicycle. Secondly, you need to make sure your frame can fit a crank-arm based power meter on your bike. This means you need to make sure there is the necessary clearance (10 mm) between the left crank arm and your chainstay – and that you don’t have a chainstay mounted rear brake. Please refer to the image below.
Are Stages power meters accurate?
Yes. Stages units are accurate to within +/- 1.5%. The industry average for power meter accuracy is 1.0% to 2.0% so this is in-line with most power meters on the market.
How long does a Stages power meter battery last?
The battery on a Stages power meter will last for 200 or more hours.
What head units does a Stages power meter work with?
You can use the Stages power meter with any ANT+ enabled head unit, as well as with a smart phone using Bluetooth SMART.
How do you change the battery on a Stages power meter?
You can change the battery on a Stages very easy. For left road and MTB crank arms, as well as for right MTB crank arms, there is a small, round battery door that pops off, exposing the CR2032 battery. For right side road power meters, there is a small door that is removed by unscrewing two small screws. You can change a Stages battery in only a couple of minutes.
Does a Stages power meter measure speed?
No. A Stages power meter measures both power and cadence. Speed is measured by the GPS in your bicycle computer. You can also choose to add a speed sensor to your bike should you wish.