Best Power Meter For Road Cycling: The Sportive Cyclist Guide

Want to know the best power meter for road cycling? Of course you do. Specifically, you want to know the best one one for you.

Well rejoice and look no further. In this post I’m going to discuss all your power meter options. Between us we’ll work this out. Trust me.

Oh right, you only just met me? No need to trust me then. Just read the article and make your own mind up.

So, I give you the Sportive Cyclist Guide to Cycling Power Meters. Let’s get powerful.

[Fanfare. Mont exits with a flourish]

A Quick Disclaimer

Now I don’t own a power meter. I keep hoping that if I write about the topic enough, one of the power meter companies might notice and send me a free one.

Fat chance. At some point I’m going to have to buy one.

And me being me, I’ve done all the research to work out which one I’d get, for when the urge to splurge finally becomes unbearable (or when my training becomes so consistent that ‘training with power’ would give me a material uplift in fitness).

I thought I’d share what I’ve learnt with you good readers of the Sportive Cyclist (and a few of the naughty ones too).

So, What Do Power Meters Do?

They measure, er, power.

Where previously you might have measured your training ‘input’ by how you felt (perceived effort) or how long your heart rate spent in each training zone, power meters allow you to do this by measuring how much force you’re pushing through the pedals.

The unit of measurement (which is a dull way to start any sentence) is the watt (as in James Watt). It’s a measurement of the rate of doing work – in other words, the amount of energy created, or used, per second.

(Translation: science, sciencey science.)

Your Eco light bulb uses 10W. On a sunny day my solar panels supposedly generate 4kW (4,000 Watts). In a sprint, Mark Cavendish produces around 1,300 watts (which is lower than many sprinters). On a good day I reckon I average 130W on a ride. C’est la vie.

Why Do You Need A Power Meter?

Because pro riders have them. Next!

Alright…

Well, the main reason would be that the data that a power meter can generate can be used to make your training more effective.

You might already use heart rate data, and specifically heart rate zones, to structure your training. Or you might go on ‘feel’ (or Rate of Perceived Exertion to the sports scientists).

Using power data is generally deemed more precise. There isn’t the same time lag in response to a big effort – immediately you can see that you’re putting out a big wattage (okay, quite big…).

(Incidentally, I’ve written A LOT about cycling training (including some sciencey science) – you can see all my posts here)

Pro cycling commentators talk about ‘W/kg’ being an important indicator of Tour de France success. If Chris Froome can get his weight right down, whilst still generating a lot of power for 30 minutes straight, riding up an Alpine climb, then he can ride away from his rivals in a race-winning move.

Increasing the number of watts you can generate for a sustained period of time is good. And the only way to know (accurately) how many watts you’re generating is to get a power meter.

Which Power Meter Do Pro Cyclists Use?

There’s no single answer to this one. It is largely dictated by the team sponsorship agreement. If the team that a pro cyclist rides for is sponsored by SRM, then it will generally be an SRM power meter attached to that pro’s bike (or bikes).

For more on the subject, here is an interesting article from Cycling Weekly.

How Do Cycling Power Meters Work?

Power meters tend to be comprised of two key elements. There is a strain gauge, which measures the force that is being put through the component, and there are the gubbins which are used to transmit the data received up to your Garmin or smart phone.

I’m not sure we need to know a great deal more than that, unless we’re another startup that has the ‘unique’ idea of creating a much cheaper power meter.

Different Types Of Power Meter

Power meters can be classified most easily by where they reside on the bike.

Here are the main locations:

• pedals
• chainring
• crank arms
• rear hub
• the imagination of an engineer (for those products that have been announced but aren’t yet available to buy)

The location of the power meter has a bearing on the power level recorded.

The point at which your power leaves your body is your foot (which sounds like a great now motto for this website). The further away from your foot that the meter is located, the more power is lost to friction, bendiness and other scientific terms.

Pedal-located power meters tend to record levels that are higher than ones found in the rear hub. By the time your power has got to there, it’s been dissipated slightly by the ‘give’ in your cranks, the friction on your front rings, chain and cassette.

This isn’t a major issue (unless you’re training for le Tour) as the relative difference remains pretty consistent so you can adjust for it (though if you’re only measuring your performance over time, then there shouldn’t be any need to).

Pedal-based Power Meters

Power meters ain’t cheap (although prices have, and continue to, come down). A sportive cyclist (which I am) might only be able to justify owning one power meter.

Thusly, the ability to switch a power meter between bikes (between your winter and summer bikes, say, and to take on a training camp holiday with you) might be an appealing feature.

Pedal-based systems have this feature. Whoop.

For a long time, Garmin had this field to themselves with their Vector pedals. They charged a pretty price for them and presumably people paid. Now other manufacturers have entered the scene, so prices have started to come down (though they still feel pretty high versus power meters located elsewhere on the bike).

Pedal Power Pluses

As mentioned, the main attraction of pedal systems is their convenience. They’re easy to fit in the first place and then swap between bikes afterwards.

You could quite easily pop them in your hand luggage for the Easyjet flight to Palma (other airlines are available, as are other Mediterranean airports), hire a road bike over in Puerto Pollensa and be testing your functional threshold power on Sa Calobra, using little more that an Allen key (hex key…).

Pedal Downsides

A key consideration with power meter pedals (and the problem in my case) is what underlying pedal/cleat system they use.

All of the pedal power meters so far released (I think – certainly Garmin Vector and the Powertap P1s) use the Look Keo pedal and cleat system. We’ve already mentioned that pedal power meters are, for the time being, limited to a small number of pedal systems. So that’s a downside if you use a different pedal/cleat type. As a Speedplay pedal proponent, that would be me then.

Pedal-based systems do tend to be expensive versus other power meter options, even with the increasing level of manufacturer competition.

Finally, pedal-based systems, given their location, are potentially more susceptible to damage, either in transit or through grounding on a particularly tight corner (which is admittedly quite rare).

Pedal Power Options

Powertap P1s - Easy to install - all you need is a Hex (Allen) key. - Use AAA batteries rather than being rechargeable or using the CR3202 coin type battery (for better or for worse). - No left-only (i.e. cheaper) option. - Requires you to have Look Keo cleats attached to your shoes... Click here for latest prices
Garmin Vector 2 - Gives you access to Garmin's 'Cycling Dynamics' (pedal stroke analysis and the like). - Seem a little more fiddly to install than the P1s. - Vector 2S is the cheaper left-only version; Vector 2 has power meters in both pedals. - Look Keo cleats required (again). - Certainly an option if you're a committed Garmin-ophile... Click here for latest prices
Favero bePRO - Also available in dual pedal and single pedal versions - the former simply doubling the output from the one power-metery pedal. - If you go 'left only' to start, you can buy a right pedal in the future to upgrade to dual power. - Yes, I'm afraid it's Look Keo cleats again... Click here for latest prices
Look Keo Power - These used to be made in partnership with Polar. Now Look make them on their own, which means that they've added ANT+ connectivity (a must in this day and age) to the pre-existing Bluetooth Smart. - That said, more data seems to get broadcast via the Bluetooth Smart channel than ANT+ (e.g. 'dead points', max/min power). - Available in single- and dual-pedal power versions. - Clearly you'll want to be a Look Keo pedal user (or be prepared to become one) if you want to use them... Click here for latest prices

Crank-based Systems

Power meters attached to the crank seem to have been a growth area in recent years, and where much of the downward price pressure seems to have occurred.

Here a strain gauge is attached to one or both cranks in order to measure the force that you’re putting through each pedal stroke.

Some companies (the highest profile being Stages, purveyors of finely calibrated power meterage to the royal family of Sky Procycling) offer a ‘left only’ power meter. Power is measured on one side only and then that number is doubled to give your overall power output.

The main advantage of ‘left only’ power meters is cost. You only need one special crank arm fitted with the strain gauge and whatever other gubbins needed to transmit the power data to your Garmin.

The disadvantage is that the overall power output becomes more of an estimate. The assumption is that both legs generate the same power constantly throughout each ride. In reality, the ‘power balance’ between your legs is unlikely to be exactly 50–50 and, indeed, will vary as you tire over the course of a ride.

The question to ask is how vital to you is the level of precision provided by true ‘left-right’ power, and are you prepared to the additional amount to get it.

The ‘traditional’ argument in favour of left-only power meters starts with the words, “If it’s good enough for Sky…*”.

(* though Sky seem to have persuaded Stages to make them a special dual-crank version…).

Crank Power Meters: Makes and Models

Stages Power Meter - Left only (unless you ride for Team Sky Procycling). - You buy the whole crank with PM attached. - Available for Shimano (Dura-ace; Ultegra; 105), other crank/bottom bracket specifications (Cannondale, FSA, SRAM-compatible) but seemingly not yet for Campagnolo (Super Record; Record; Chorus are apparently coming soon). - Battery life 200 hours - standard coin (CR2032) battery. - ANT+ and Bluetooth Smart ready. - Adds only 20g to base crank arm. - Accelerometer based cadence. - Newer version has '200% increase in battery door interface strength' (which is a relief...). Click here for latest prices
4iii Precision - The strain gauge pod (a la Stages) was originally planned to be self-installed; now you send your crank arm (or arms, when they get round to offering a dual left/right option) Click here for latest prices
Pioneer - Looks like its a chainring spider-based system (in that there's a big red, er, thing in one of the spider 'windows' (technical term) but the force meters (or meter if you're going single left) are installed on the crank arms, like the Stages and 4iii offerings. The 'red thing' contains the battery plus other gubbins). Click here for latest prices
Verve Infocrank - Dual leg (which suits those with two legs). - ANT+ only (not a problem for most use cases). - Custom-designed crank arms that are specific to Infocrank - so you'll have to swap out your entire existing chain rings/front drivetrain fandango. Click here for latest prices
Watteam Powerbeat - Very good price - $499 for a dual-sided power meter. - You install (i.e. glue) the power meter to your own crank. - Sales so far have been very limited - and only in the US. - Somewhat beset by technical issues, Watteam plan to start shipping again around Christmas. Click here for latest prices

Chainring Power Meters

I’ll try not to insult your intelligence by noting that these power meters are located on (in?) the chain rings (the larger set of rings at the front of the bike).

We’re one (small) step further away from the producer of the power (your foot), but you’ve got to imagine that the difference in recorded power between chain ring and crank-based systems would be lost in the +/–% inaccuracy that blights any good power meter system.

In terms of convenience for moving between different bikes, chain ring based systems involve the most faffing around. If portability is a consideration, I’d be looking elsewhere for my power meter type.

Chainring Power Meters: Makes and Models

SRM Power Meter - Historically deemed the gold standard in the world of power metering, so SRM's marketing focuses very much on accuracy, quality and reliability. Which means they're quite pricey... - One for each major drivetrain manufacturer: Shimano, Campagnolo, SRAM. Click here for latest prices
Quarq - Built in cadence sensor (using an accelerometer rather than a magnet). - Measures right and left strokes independently. - Top of the range is Quarq Elsa RS which is Shimano only. - Next down is the Elsa R, which apparently works with most 10- and 11-speed chainrings with the right bolt circle diameters (130mm/110mm). - Riken R sits below the Elsa R with the main difference seemingly that the latter comes with lighter 'Exogram' crank arms. Click here for latest prices
PowerTap C1 chainring power meter - Here you're buying the chainrings whilst retaining the rest of your crankset, so you'll want to check that what you have is compatible (For instance, having a look at the table on the Powertap website. -Dual ANT+/Bluetooth. - Very reasonably-priced for a dual-leg system. Click here for latest prices
Power2Max - Another good value crankset-based power meter - Will work with some cranks (i.e. certain Rotor, Cannondale, Specialized and SRAM models) but if you ride Shimano or Campag then you'll need to buy new cranks with the power meter. - Presents left and right power by taking the downstroke on each pedal to be that side's power (so an estimate). - Two (broad) versions: Classic (the older model) and the Type-S (the newer one). Click here for latest prices
ROTOR INpower - Strictly speaking the power metery gubbins for the ROTOR INpower sit INside the crank axle, rather than being on the chainrings per se. No matter - I've included it in this table because I can't be ARsed to make another table just for this... - The system uses ROTOR's crank arms rather than your existing groupset. Left-only and full dual-power options available. - Work with asymmetric 'Q-rings' (if those are your bag). Click here for latest prices

Rear Hub Power Meters

Hmm, the ‘does what it says on the tin’ trend continues. For this category of power meter, the strain gauge resides within the hub on your rear wheel (the bit that goes click-click-click (technical) term when you’re freewheeling).

And the term ‘category’ probably overstates things. For reasons I’m not sure about, only one manufacturer makes a rear hub PM, and that’s Powertap with its G3.

The G3 has been available for ages, so by all accounts it is accurate, reliable and offers good value. Moving it from one bike to another is pretty straightforward (you’re just changing a wheel), provided both bike share the same gearing set ups.

Of course, if you’re a “one bike, two sets of wheels” kind of cat (e.g. you run a sturdier training wheelset and a lighter set of ‘race wheels’), then you’re going to need two rear hub power meters (or do one activity sans power).

As mentioned at the top of this article, your recorded power level will differ slightly depending on the location of the power meter itself. The rear hub is a couple of steps removed from the power generating source (which we’ll call, ‘your foot’) versus, say, the pedal, so you can expect your power recorded here to be a few watts lower.

Rear Hub Power Meters: Makes and models

Or make. And model.

No funky table required here.

The Powertap G3 can even be bought as a standalone rear hub, in which case you or your tamed bike engineer will need to build a wheel around it, or pre-fitted on a wheel. If it was me (and it could well be), I’d buy the power meter as part of a wheelset.

Comms-wise, it can talk ANT+ or Bluetooth Smart, provided you have correct ‘cap’ installed. Apparently a dual-protocol communication cap is on the way (and we all need one of those…).

Cleat Power Meter

Another category occupied by a single maker, but in this case a much more recent entrant to the market.

The Zone DPMX (“catchy!”), made by Brim Brothers, attaches to you rather than your bike. Or rather it attaches to your shoes. The strain gauge fandango sits within the cleat (on t’underside of your shoe); the electronic transmission gubbins are in a pod on top of the shoe (where the straps are).

(UPDATE (February 2017): Unfortunately, Brim Brothers have gone bust… so the Zone DPMX never quite made it to market. And I suppose it never will…)

The good/bad news (depending on your pedal persuasion) is that it’s (currently?) only available for Speedplay pedal and cleat users. Which just happens to include me. Joy.

So. If you are a Speedplay user, or plan to become one, then this could be the ideal multi-bike solution. Providing you have Speedplay pedals on all your bikes (and you tend to wear the same pair of shoes) then moving the power meter between bikes is just a case of walking from one bike to another and clipping in.

It could even work in a holiday-hire-bike scenario. As well as taking your cycling shoes, you’d just remove your Speedplay pedals from your bike and bring them with you. That’s what I did on my last training camp family holiday in Majorca, and I’ll probably do the same when we re-run the fun next week (NEXT WEEK PEOPLE!).

As far as I can tell, they only communicate via ANT+ (which isn’t a problem). There are single leg (foot, shoe…) and dual leg versions. The dual leg version costs twice that of the single leg, which is logical.

A word of caution though. The Zone has only just started shipping, after a very length gestation period (with at least one crowdfunding campaign). I haven’t yet seen a detailed review that tests their accuracy (certainly not a recent one from DC Rainmaker). Possibly one to wait and see.

The Elephant In The Room

Which is an analogy.

The elephant is Shimano. The ‘room’ is the power meter market for everyone else.

After much non-secrecy, Shimano has revealed details of its own power meter, which nestles in amongst the other components of the (for now) Dura-Ace groupset.

I don’t think they’ve said precisely where the strain gauges are situated, so I haven’t put it in one of the location-based tables above. Images show a pod located in the chainrings (so it’s safe to say it’s not a rear hub or pedal-based system).

Clearly, this is a bit of a cliche game changer for the power meter market. If a power meter ships with a groupset then it becomes the de facto choice for a lot of riders.

Right now, Shimano is targeting the Dura-Ace crowd, but where Dura-Ace leads, Ultegra and 105 tend to follow. Power meters for the people! (Free Tooting!)

Watch this space people.

Measuring Power On Your Indoor Trainer

Of course, you don’t have to get an expensive power meter in order to get a sense of the power you produce.

You can buy an expensive indoor trainer instead.

If you have a suitable indoor/turbo trainer, you might find that it’s already measuring your power and broadcasting it so your Garmin can pick it up.

Alternatively, if you have cheaper turbo that doesn’t contain a power meter, there are some apps (such as Trainerroad) that can calculate an estimate of your power based on your speed and the resistance curve for your particular trainer.

Don’t ask me how it works, but it certainly seemed to get my juices flowing when I tried out Trainerroad for the first time (which you can read about here). Even the pretence of power meterage appears to get me excited…

‘Power Meters’ That Don’t Take The Strain

There are alternative devices that attempt to measure (or, in certain cases, estimate) power output without employing strain gauges.

Powercalifragilisticexpialidocious

For many years, PowerTap have sold a ‘power meter’ that takes the form of a heart rate strap, called the PowerCal (originally it was branded CycleOps, which I think is in the same stable of companies). The gubbins within the strap calculates and broadcasts (via ANT+ or Bluetooth Smart, depending on which version you buy) an estimated power number, based on, er, your heart rate whilst you’re riding.

Since that broadcasted number appears on the screen of your bike computer (let’s call it an Edge 520) just like every other directly-measured power meter, I reckon that I’d get excited about it in just the same way as I do with the calculated number from TrainerRoad. And with the Powercal costing at most $120/£100, that’s a cheap way for me to get my power meter kicks…

The West Wind Shall Blow And We Shall Have Power

In August last year, US-based Velocomp kickstartered their ‘PowerPod’ power meter, raising $128k versus a target of $50k. Like the PowerCal, it uses ‘algorithms’ to calculate a power number, without using strain gauges. Where the ‘Cal uses heart rate, the ‘Pod uses wind.

Essentially it’s a little, er, pod (?) that sits beneath your handlebars, with a little air intake to measure wind resistance and, within its innards, sensors that measure acceleration, pressure changes… that sort of thing…. And then [magic happens] it broadcasts out a power to your (let’s call it an) Edge 520.

Again, at $299, it’s a lot cheaper than power meters that directly measure power on the bike. Whilst not (quite) as portable as the PowerCal (the PowerCal is, after all attached to the human not the bike), it’s not far off. The PowerPod is very much an option for a power meter that can be taken on a training camp family holiday without needing to jettison your child’s favourite toy or to take along your full Park Tools Bike Mechanic kit.

And Then There Is Strava…

[Wistful] There’s always Strava. [/Wistful]

I can’t quite remember what is available to Strava Summit users and what comes in the free version.

But.

When I record a ride on Strava, it provides me with an estimate average power for the session (I think free users can see this number). Then, Premium users (like moi darling) can see an estimated power curve (i.e. an estimate of how much power you can sustain for 10 seconds, 30 seconds, 5 minutes etc) plus some analysis of how much time on the ride you spent in each 25 watt range (e.g. I spent, say, 6:08 minutes in the range 150-174W).

With this information I can then reliably assess whether I’m in shape to win this year’s tour. And to be fair, it’s been accurate in its predictions so far.

I wrote a post on how Strava calculates power data. I don’t know if its correct. But then I could say that about most of what I write.

Cheap, Portable Power Meters – It’s The Future (I’ve Tasted It)

Power meters have historically been expensive and hard to move between bikes. Or even more expensive and marginally easier to move between bikes.

Surprising to say, some companies have spotted an opportunity to make a cheaper power meter that is easier to move between bikes. And this tends to get people excited.

Which perhaps explains the runaway success of another crowd-funded product, the Limits Power Meter. Limits, who have designed a power meter that fits between the pedal spindle and the crank, raised over $500k on crowdfunding platform Indiegogo.

It certainly sounds interesting and, at $385 when it goes on general release, good value (though slightly less good value to us post-Brexit Sterling users…). We wait with baited breath (though the slightly sceptical DC Rainmaker suggests we might be waiting some time…)

So How Do I (You) Choose?

If I knew the answer to this then I would already own a power meter.

For me (and most people), it will come down to price and flexibility. How much price am I prepared to pay in order to make it relatively more easy to switch the power meter between bikes.

The Zone shoe-based system looks attractive (though not for non-Speedplay users) but is not yet shipping. The Powertap rear wheel power meter (the G3) could solve my requirement for a new set of wheels.The Stages crank power meter has that certain je ne sais pas that comes from being used by Team Sky (even if they get paid for it) – damn you Montgomery for being swayed by such shallow factors!

Decisions decisions…

Conclusion

I want a power meter. I am convinced that owning one will magically transform me into a semi-pro cyclist (at age 37, I accept that a full pro career is out of reach).

Hopefully you’ve found useful this quick spin around the world of power meters and the summary of what options are available for the power-hungry cyclist.

If you have any questions, do ask them in the comments below and I’ll endeavour to answer them as best I can. If this post has tipped you over the edge into ordering a power meter (or indeed anything cycling-related), please use one of the links in the post and I’ll hopefully get a small affiliate commission.

In the meantime, happy cycling!

Monty is an enthusiastic road cyclist with only moderate talent. He started Sportive Cyclist in 2013 to record the journey to his first 100 mile ride, the RideLondon 100. Over time the blog has expanded to include training advice, gear reviews and road cycling tales, all from the perspective of a not-very-fit MAMIL. Since you're here, Monty would also like you to check out his YouTube channel. Also, Monty really needs to stop referring to himself in the third person.

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