How to Install a Power Meter

Most power meter installs are easy. The reason the question gets asked is that the consequences of getting one small step wrong are invisible — a meter installed at the wrong torque, or with the wrong crank length entered, works perfectly and reports numbers that are quietly wrong for as long as you own it. So this page covers the mechanical procedure, which takes minutes, and then the three setup steps that actually determine whether your data is worth anything.

Before you order: the fitment check

This is the step that saves a return. What you need to confirm depends entirely on the format you are buying, and the difference is stark: pedals need almost nothing checked, crank-based meters need real homework. Power meter pedals vs cranks is the full version of that trade-off.

What to look for in a power meter you intend to fit yourself

A published torque figure. Install torque changes the resting strain inside a strain gauge, which is to say it changes what the meter reads at zero load. A maker that publishes a number has told you how to avoid introducing an error on day one. Garmin and Favero both do.

Tools in the box.A long 8 mm hex key is the specific tool a pedal install wants and the one most home toolkits lack. Favero includes one.

A documented setup procedure. Crank length entry and zero offset are not optional, and a maker whose app walks you through both is doing you a favour.

An install you can reverse. Pedals come off as fast as they go on, which matters if you have a trainer bike and an outdoor bike. A bonded arm or a spider does not.

Honest fitment limits.Favero publishing "no extenders, no shorteners, nothing thicker than 15 mm at the thread" is more useful than silence, even though it reads as a restriction.

The short answer

The easiest power meters to fit yourself

#	Product	Best for	Score	Price
1	Favero Assioma Duo If you want the install to be a non-event, buy pedals — and these come with the hex key and the clearest documentation.	Easiest install of any power meter	9.3★★★★★9.3 out of 10	$539.97 · View on Amazon #ad We may earn a commission · Price as of October 5, 2026
2	Garmin Rally RS210 The clearest published install procedure in the category, and no cleat change if you already ride SPD-SL.	Best-documented pedal install	8.8★★★★☆8.8 out of 10	$899.99 · View on Amazon $1,199.99Save 25% #ad We may earn a commission · Price as of October 5, 2026
3	4iiii Precision 3+ The crank install is genuinely easy — a crank bolt and two pinch bolts — but the compatibility work happens before you order, not after.	Easiest crank install, if the part matches	8.6★★★★☆8.6 out of 10	$437.49 · View on Amazon #ad We may earn a commission · Price as of October 5, 2026

Installing pedal-based power meters

1. Clean and grease the threads.Clean the crank threads, then put a thin layer of bike grease on the pedal spindle. Garmin's manual calls for exactly this, and it matters more than it sounds: a dry install can gall the threads, and a galled crank thread is an expensive mistake.

2. Right pedal first, and remember the left is reverse-threaded. The drive-side pedal tightens clockwise; the non-drive-side pedal tightens counter-clockwise. Thread each one in by hand for a few turns first to confirm it is engaging straight — if it resists in the first couple of turns, back it out and start again rather than forcing it.

3. Torque to the manufacturer's figure.Garmin specifies 25 ft-lb (34 Nm). Favero's Pro RS manual specifies 30 to 40 Nm. Use a torque wrench if you have one; Garmin's fallback instruction is "as tight as possible using a pedal wrench", which tells you this is a firm fitting, not a delicate one.

4. Rotate the crank and check chain clearance. Turn the cranks a full revolution and watch the chain. If it rubs the pedal body, Garmin permits one pedal washer between the spindle and the crank arm — one, not two. Favero also supplies washers for clearance from the chain or frame. If one washer is not enough, that pedal and that frame are not a good match.

5. Check the spindle protrusion, if your maker specifies it.Favero requires the spindle end to protrude at least 1 mm beyond the crank thread, which is why cranks thicker than 15 mm at the threaded area are excluded.

Installing a bonded crank-arm power meter

1. Remove the existing non-drive-side arm.On a Shimano Hollowtech II crankset that is the crank cap, then the two pinch bolts, then the arm. The bottom bracket stays where it is.

2. Fit the new arm.Slide it onto the spindle, snug the crank cap to set preload, then torque the pinch bolts to the crankset maker's specification — this is the crankset's figure, not the power meter's, so use Shimano's or your manufacturer's number rather than a figure from memory.

3. Check clearance. Turn the cranks and confirm the bonded pod clears the chainstay and anything else close to it. Pods sit inboard, and frame clearances vary.

4. Zero offset, then ride. A refit always needs a zero offset, because you have just changed the resting strain in the sensor.

Installing a spider or a complete crankset

This is the one case where we would point most riders at a shop. A spider swap involves separating the spider from the crank, and a crankset install involves the bottom bracket interface, preload and chainline. None of it is exotic, but the failure modes — a creaking bottom bracket, an over-preloaded crank, a chainline that shifts badly — are tedious to diagnose and easy to create. If you already change your own bottom brackets, you do not need this paragraph. If you do not, the labour cost is small against the price of the meter.

The three setup steps that decide your data quality

1. Enter your crank length.Do this before the first ride. Power is torque multiplied by angular velocity, and torque is force at the pedal multiplied by the crank radius — so a pedal-based meter cannot compute power without knowing how long your cranks are. The figure is stamped on the back of most crank arms. Enter 172.5 mm when you ride 165 mm and every number you ever record is about 4.5% out. On Favero pedals it is set in the app; on Garmin it is in the sensor settings on the head unit; Magene sets it in the Magene Utility app. Re-enter it every time the pedals move to a different bike.

2. Run a zero offset. Unclip, let the cranks hang still, and run the calibration or zero-offset function from your head unit or app. Do it when the meter is new, after any refit, and after a significant temperature change — a meter that has been in a cold garage is the classic case. How to calibrate a power meter covers how often this actually matters.

3. Do one dual-recorded ride. Record your trainer and your new power meter at the same time for one steady session, then compare the averages. You are not looking for them to match — they will not, and how accurate are power meters explains why a few percent of offset between two honest devices is normal. You are looking for a sane, consistent difference. A 15% gap means something is wrong, and the first thing to re-check is the crank length.

The four mistakes that cause most bad power data

Wrong crank length. The most common, the most invisible, and the easiest to fix. Check it first, always.

No zero offset after fitting. You changed the resting strain when you torqued the pedal. The meter needs to be told.

Under- or over-torqued. Under-torqued pedals can loosen on the ride, which is a safety problem as well as a data problem. Over-torqued risks the crank threads. Use the published figure.

Two washers instead of one.Garmin says one pedal washer per side, maximum. Stacking washers to clear a chain changes the pedal's position relative to the crank and is explicitly warned against.

What to do with it once it is fitted

Test, then train. An FTP figure from your own meter is what turns the install into a training tool: how to do an FTP test covers the protocols, how to improve your FTP covers the block that follows, and the best power meters is the page to go back to if you have not bought one yet.