The Problem with Power Meters
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- Опубликовано: 13 июн 2024
- Power meters are fantastic pieces of equipment. However, there is one huge problem with them: each one gives a different reading, and some vary wildly in their accuracy. Can power meters actually be relied upon, or are they just expensive random number generators?
Welcome 0:00
Categories of Power Meters: Pedals, Cranks & Hubs 0:25
Power Pedals & Power Cranks 2:39
Accuracy of Power Meters 3:12
Does price affect accuracy? 5:03
Can you make a power meter more accurate? 5:28
How seriously do you take your training and data analysis? 6:39
What power meter would we suggest? 7:22
Conclusions - Tell us your experience in the comments 8:04
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Do you own a power meter? Let us know in the comments 👇
Yes 4, 3 that I made myself and 1 I got second hand.
Favero assioma duo shi 👌
I have Favero Assioma DUO on my road bike, Magene PES P505 Base on my CX bike, Sigeyi AXO on my XC mountain bike and then I have Elite Direto XR trainer. I used to have InPeak Powercrank, but I sold it to my friend, because after my injury and following two surgeries I unfortunately have quite a significant disbalance. Compared them all against the Assiomas and they all track really accurately against each other, yet when I had the InPeak, I had to scale it up by 2% to get it in line with the other measuring sources (splitted the Assiomas into UNO for that test).
I have/use 3 4iii powermeters on road bikes, 2 Quark and Garmin Rally 2.0 in MTBs.
Only issues I've found:
Garmin pedals is realli difficult to go over 800 watts, no matter the effort.
on the Wahoo Kickr core, I found ERG mode stupid hard, 165 watts is equivalent to riding a 15% up.
the rest of the power meters work fine for me, both in circuit and open roads. Only thing I would change is recharging, as changing batteries on 6 pieces of equipment is not cost effective and a pain in the a$$
I have a stages gen2 single side I picked up cheap on fleabay.
Only had it a few weeks so still in the honeymoon phase but, once I had overcome the upgrading to a modern BB and sorted the well known battery contact issue, it seems consistent and looking forward to seeing how I'm doing more clearly out on the road.
Of course I did have to go out and break the 1000W barrier, but I'm over that now 😂
The biggest problem with a power meter is that it provides an exact measure of how much I suck as a cyclist
Nope.
No problem > Just Ride & Enjoy It !
Good luck...
😂 me too!
You can always change the slope. There's no good reason you can't have better numbers than MVDP
Hah! I feel you brother
Sim[ple : Don't buy a power meter until you've watched & understood the Shane Miller / GP Llama or DC Rainmaker reviews & analysis.
I used DC Rainmaker reviews both when choosing my power meter as well as my indoor smart trainer.
Agreed 100%. For any sports tech, really.
This essentially boils down to don’t buy the R92000P, R8100P, or R9100P.
@@weiwenng8096 😂 exactly!
But for PM noobs this is brilliant. Well done GCN
Assioma Duo are the business. Super easy to swap between bikes if you're fortunate to have more than one. I use mine on the indoor trainer and outdoors for consistent readings. Accuracy is excellent.
Have these on my primary road bike. Very impress for the value!
I also use Assioma Duo. I've been a bit of a nerd and compared against my Wahoo Kickr. I did the 1 hour FTP test on Zwift using Wahoo Power meter, whilst simultaneously pairing my pedals to my Elemnt Bolt running the same test. I've done this 3 times and its never been more than 3 watts different either way.
To sum up, Shimano power meters are notoriously inaccurate.
Exactly you definitely don't want a dura ace shimano power meter. That belongs in the parts bin.
Ultegra 8100 on par or even worse 🥴
I've got a 9100P DuraAce powermeter and it's shit around 30W underreading compared to my srm, a kickr and asioma pedals
Yea all I hear is how crap the Shimano crank powermeters are ... and how insane good Favero is... and here the message seems to be the opposite.
@FliskerX the video doesn't mention either Shimano or Favero.
I thought my power meter pedals showed I produced more power changing from 172.5mm cranks to 170mm. They actually showed the importance of remembering to set the crank length to accurately measure torque. Sigh.
I picked up a used single sided crank power meter a few weeks ago - spent the winter months on the indoor trainer so I got used to seeing the numbers.
Very happy with the purchase so far. A positive surprise is that I am now much more tolerant of riding into a strong headwind as now I see that I truly can be putting in more effort even if it results in a slow speed. Like of course I realised that I *must* be putting in more power if my heart rate is going up but it's still nice to see it for sure.
So for me it has been worth it just to compare myself with myself, and makes you realise even more how useless comparing average speeds often is.
Amen. Average speed doesn’t mean anything. My outdoor bike is relatively heavy and not very aerodynamic but my FTP is 4 w/kg whilst people who can afford fancy bikes and aren’t as fit fly past me
That's great! Often having power numbers just gives a bit more context 🙌 That can really help with motivation!
Be careful though. I had a single side PM and switched to pedals. My power readings with the single side were 10-20% higher than with pedals. My left leg is stronger than my right I learned with the pedals, inflating my average power on rides.
I’ve got the Assioma spindles. Completely changed my training. Love the data it gives me
I’ve had the Faverro Assioma’s for 5 years now. They just work and are consistent. Fit and forget. Super easy to swap between bikes if you need to. Support from Faverro is excellent if you do ever have a problem.
that's great to hear!
I don't have a power meter nor do I planned to get one. I don't race but I do like to ride bikes, so I put the money of power meter into getting an entry level tubro trainner. By doing so, I can ride indoor when weather isn't good and get a stationary platform to dial in my riding position.
Haha, you can’t lose! 😂😂😂
Great idea! A power meter is great but certainly not a must have to enjoy cycling. The turbo trainer is a game-changer for those wet weather rides! Enjoy and don't forget join the GCN Zwfit club 👉gcn.eu/Zwift
And my TacX tells me wattage anyways. Ride based on heart rate, indoor train on power.
If you are using Shimano power meters, they are known to be very inaccurate on the right side
I remember one day after a good month or two of training, I swapped my left sided stages pm off my training bike onto my race bike. I calibrated it and it gave a different number than usual, but I thought nothing of it. So I set off for my 3hr hilly loop and felt great. The ride was effortless and I was amazed at the power I was doing on the flats, and up the climbs. And thought "Man 300w's feels really easy up these climbs! I must have got fit all of a sudden. My training must have all come together and my body has finally adapted! Wow this is what it feels like one of those young A graders. This is great!" Then after a few hours I suddenly thought..."Hang on a minute. This can't be right, better stop and check the pm". And lo and behold I'd forgotten to tighten up the 2 pinch bolts on the crank! And it was only staying on with the help of it's shimano safety tag and dust cap! My short stint of being "a good cyclist" was over, and I rode home feeling rather silly at my usual 180 to 200w's :( lol
Hahaha that must have really felt like a hit! 🤣 That said, if you were feeling good you should be focusing on that! Feeling good on the bike is the most important thing 🙌
When I started using power pedals I didn’t know I was supposed to calibrate it before every ride 😅 and I had a goal off hitting 300w for an hour. And went from 240 to 320 very quickly 😅 and got a little suspicious and it was way off. Took me 6 months to beat any off the watt records xD
Nice balanced video (though you could've mentioned the expensive low-fidelity elephant in the room). Many riders claim that you don't need accuracy, all you need is consistency, but they don't know how or even bother to measure consistency. I think that the need for accuracy depends on what you're doing with the data, and there are widely different uses so there are widely different needs for accuracy and precision. Training FTP is one of the least demanding things you can do with a power meter, so a single-sided meter (or a dual-sided Shimano) are probably fine for that. Measuring CdA and Crr are *very* demanding uses, so you absolutely need high-fidelity data for that purpose.
I used Shane Miller/GP Llama's reviews, and replies he gave me to questions I asked him in the discussion section of his RUclips videos, to decide what power meter and indoor trainer to buy. Great guy and he's thorough, precise, and data driven. What more could you ask for? BTW, I have been very happy and impressed with the performance of the Wahoo KICKR V.6 trainer and Assioma Duo Shi power meter pedals he recommended.
The Wahoo KICKR is great isn't it! 🙌
@@gcntech Absolutely! Especially the 6th edition with WiFi. Rock solid connectivity! 🥰🥰🥰
Got myself a stages single-sided power meter 2 months ago. It totally change the game for me. I feel more motivated and consistent with my training because I can see how my capabilities on the bike improve.
The purchase of assioma duo was useful for me. because the distribution between the right and left legs turned out to be more important than the power itself. Now I distribute the load more evenly.
Albeit, prohibitively expensive. the Rally RS200 is extremely accurate and this is well-documented but again, it’s expensive. The cycling dynamics data is out of this world and I’ve found it extremely helpful.
As you said the consultant readings are what you need, then you know if you are improving or not. Good video.
Love how GCN has got so nerdy over power meters. Very well explained, and as far as i can tell, 100% accurate 👍
They really did well to talk about it in a diplomatic way to piss any sponsors of.
So if one can read between the lines...
Quite suprised about the quality compared to other PM reviews
Ollie getting nerdy... no that would never happen 👀
Single sided pedal powermeter user here. Garmin Vector axles inside Rally XC bodies. Bought so I can both monitor training and make sure I ride easy enough on first days of multi day bikepacking rides (as vectors to begin with). Self assessment and riding on feel only gets your so far when you feel so fit and fresh its easy to do too much too soon. Very happy with them I am too (power meter parts now more than 5years old)
Exactly my experience. I use an SRM pm on my road bike and a Quarq on my gravel bike. Quarq is >10W more optimistic
I bought a pair of Garmin Vector 3s around five years ago after wanting to see how my spin bike power data translated to that of my bike rides. I found that they are really quite separate and while they are good indications of my general fitness (when I have some), they are best only compared with themselves; other than for anecdotal interest.
Have used Garmin's pedals for the last couple of years and have now bought the newer version. There is 40 watt difference on the lower side compared to my calibrated wahoo hometrainer and compared to my team mates I'm pushing far to little. They are updated and calibrated to 165mm crank. Any suggestions on getting them dialed in to show a higher watt so it can be more correct?
GCN Tech, Your videos always make me happy, so I subscribed!
Awesome! You're comments always make us happy 🙌
Most useful way to compare efforts is to use power vs HR instead of power (or HR). There are many external factors such as weather (esp. heat), sleep and nutrition that can affect your readings, so having two values as well as a training diary makes it a lot easier to put the data into context.
Absolutely correct, HR versus Power is an excellent measure which is independent of wind, slope, road condition and bike weight but it isn't independent of sleep and nutrition. If I ride undernourished or having had a bad nights sleep, I can see that immediately in my data, needing a HR of 150 to achieve 150W output over any length of time.
3. RPE. Heart rate, power and importantly RPE. Each one is a window into performance. If you want a full picture, use all 3.
@@geoffnash2609 I find it hard to arrive at a consistent measure of RPE as it so much depends on my mood, the weather, the head wind and temperature and being cut up by passing cars or not.
I got the assioma duos, very happy with them on all of my bikes
I have a 4iiii Precision 3+ single sided crankarm power meter. It has really helped with my outdoor training. It does read a little higher than my Wahoo trainer, but I don't mind as it is a consistent reading that I accounted for with power balancing..
generally speaking, your power will be higher on the road naturally (heat loss and micro recoveries) . If you wanted to get nerdy, borrow/use two computers or a computer and your phone app. Link one to the trainer and one to your crank and do a session on the trainer and compare numbers.
Consistency is the key right! As long as you can use your power meter for good training 🙌
My 4iii reads lower than my Wahoo trainer 🧐
I’ve compared the numbers side by side on Zwift / looking down at my Garmin
After training all winter on the indoor training with its own power meter, i have now started to train outside using my oedal based system. But the difference in numbers is quite profound. Maybe 20 less watts on average. Although I'm aware of the discrepancy, I still struggle to aim for lower numbers when outside
Favero Assioma Duo Dual pedals are the only way to go if you want non faff, instant connection, and dead consistent performance imo.have 3 pairs on diff bikes all read identical.
I have two sets of duo and they have been good. Sure some issues but Favero has always taken care of me. I will always buy their stuff going forward.
My Garmin pedals read quite a bit less than my smart trainer. I had a crash with the pedals but I don‘t think they got hit that hard. Which one would you trust more?
I love tech and found the watts data so interesting for about three years. It allowed me to get more powerful sprints. I then just started using heart rate more, as it's a better metric to measure my actual fitness and effort levels. It's still fun to see if I hit 1kw on that sprint, but isn't useful for anything other than FTP to me.
I use a 4iiii power meter on my left crank. My Kickr core output is around 10% higher so I changed the scale factor on my 4iiii so it matches my indoor training. Although I still feel that indoor training is harder..
great video, I will second one point glanced over in this vid. for 90%+ of riders, all they need to get value out of the PM is repeatability. while it's nice to know how I compare against others on Strava segments, from a training and improvement standpoint, all I need to do is compare where I am now against where I have been historically; the actual number doesn't matter, just need to see improvements or reductions in power. I will share that I have 4 PMs, my cinch PM was 20%high for over a year before I caught it and it messed up all the Strava power curves for that time. Best to keep an eye on accuracy too when using multiple PMs. Anyone know how to easily remove/ignore all Strava PM data from one meter in a single step?
I had quite the eye opener when I used to train exclusively on a Keiser m5 elliptical. I could produce 250w on there just before my LT1 for an hour. On the bike I could only do 120w! Had no idea power difference would be so big.
Great advice 😊
Having used a Power2Max campagnolo PM for years (before the bike was stolen) I can say that aside from the battery running out it was faultless. ANd required NO maintenance whatsoever. I got it second hand and it was worth every penny.
I've since used a Stages LH only PM which was frankly not good enough. I couldn't gain any form of consistent numbers. High indoors. Low outdoors. Sometimes in the right ballpark. Even when calibrated. The lack of consistency was really frustrating.
Moved to Wahoo POWRLINK now, and they seem to be really good.
TL;DR: I do think you get what you pay for.
I stick to the same make and model to maximise consistency across bikes and have tested them against other PMs (indoor trainer etc) I found Rotor PMs reliable and consistent.
I found the difference between my Garmin pedals and my Tacx trainer was fixed when I put a trainer tire on my bike. The accuracy went from 15-30watts to +/-5watts
Gonna try these out 💪
Going on my 6th year with favero assioma duo pedals. I’m less concerned with their overall accuracy and more concerned that they are consistent. As I only use one power meter I’m always measuring against the same thing and just looking for improvements over time, or targets for racing.
consistency is key here, as if they reported wildly differing numbers, that would be far from ideal!
Great advice zeroing it before every ride. My last ride was at an average 350W, but I'm pretty sure I didn't push all of them, so something is off...
I use speedplay single sided excellent and as I always use these it’s then consistent 😊 Pete 🚴👍
Yes!I have Garmin v3 duo on my road bike! with Heartrate monitor!
Why is it that we can get power numbers generated by e.g. a Garmin sports watch when we go for a run, but need specific meters to do the same for cycling?
One thing to watch is getting rogue readings when the battery gets weak. This can mess horribly with your data. I had a Stages dual side for a while with batteries in each crank arm and saw few benefits as my r/l balance was close at about 48/52. Keeping up with the battery changes and the rogue readings was a pain. I’ve single sided Stages now that has been mostly very well behaved and gives me all the insight I need.
Does anyone know of a power meter pedal with one side SPD and other side flat? Or can I just retrofit that onto a measuring spindle from Garmin or assioma?
I had a power meter for a while and then it broke. Couldn’t be bothered to buy another one so I went back to just using a HRM. Then the HRM broke so I gave up with that too. Has giving up on tech it made me any slower? Not really.
Funny how so far there’s been a heap of criticism in the comments but not many answering your initial question.
I own the Assioma Duo pedals and I love em. They are also consistent with my Wahoo Kickr trainer.
If you're not training, One of the best reasons for a PM is to track calories. Super accurate and consistent compared to the differing ways that garmin, Wahoo and Zwift estimate calorie burn.
I ride indoors on a Wattbike Atom and outdoors on a bike with a Quark powermeter. Indoor FTP is about 15% lower than outdoor FTP. As I tend to ride outdoors more in the Spring to Autumn it's making my Winter training feel especially effective this year!
What training have you been doing this year that has made you fitter in summer?
@@gcntech hours, and hours, and hours of zwift (and sneaking out occasionally on the mtb) . Pace partner rides, intervals and races.
Great video. Spells out very clearly why I simply cannot be arsed to buy one. Just ride ✌️
What would you recommend, stages or 4iii over Shimano power cranks as Shimano have had problems recently with accuracy ?
Look at Magene.
if you are looking for left side power meters, even though i bought stages, i would recommend 4iiii, not that stages are bad, but they seem to be going out of business, when i visit their website, every single item is out of stock, even the factory install options.
Good show. I m interested in powa meter, still holding off till they less pricey. Noce to know the nuts and bolts of the accuracy, for different types and where they are located. I was most interested in how they work. Do they use a piezoelectric, crystal? I think I'm wrong I dont know.
They use strain gauges, a small electrical current of a known constant value is run through a maze of foil that is boded to the surface of a material (crank arm, pedal spindle, spider etc.) and the resistance is measured, as the material deflects under load of a known weight so does the foil and the resistance changes, this data is used to calculate the power being put through the material.
meanwhile you might watch some GPlama videos ;) for a lower budget assioma is a good choice (only price is lower, not performance and accuracy;) )
For pacing my effort on a ride, that possible 5% inaccuracy isn't important. The power numbers fluctuate way more than that from second-to-second, anyway. That's why the 3-second averaging is common. So my left side only meter is fine for me and very useful.
Do not buy a PM from Shimano. As simple as that. Just go watch some known testers (GPLlama, DC Rainmaker et al.) rip Shimano a new one.
Are there power meter for flat pedals?
A single sided crank arm can be changed between bikes of same crank length in 5 min. Especially is same pedal type.
Four different power meters across four bikes (two P2M, one Quarq, and the trainer bike on the Kickr). Add in the Assioma Duo pedals, and I've used those across the different bikes at times. as mentioned, get two head units, then ride at a steady pace and compare the 3/10/30 second averages. For my stuff, its all within a couple percent at most.
Because these are all quality powermeters that just work.
Does Shimano fund GCN? Is GCN tech independent in its analysis? The reason I ask is that it seems odd not to mention the issues identified by DCR and Shane Miller.
I have assioma favero I have tested them several times against other power meters that are +/- 1% and they are always on point.
I use a Stages crankarm power meter. The most important thing is consistent readings.
Same. My best judge is, every couple of months, I line my bike up on the same 5.5 mile climb (~4.5%) and time myself to the top. The power meter helps manage the effort, but isn't my (sole) indicator of fitness.
same, they seem to be going out of business though, nothing on their website is available.
Since about 6 weeks I have a new bike with single sided strain gage powermeter. The most significant change seems to be that now It sums up my spent calories coming out much lower, compared to the time where Starva / Apple Health used more or less heart rate and data provided by my Wahoo comp.
Did you use these calorie counters to moderate your training?
@@gcntech Not really, but when you do a let say 80 km training, and now - with the powermeter - you "only" did about 6000 kJ, but before you got about 9000 and apple health credited a 200% of movement target, its somewhat disappointing...
Double sided Speedplay. Recently had a bike fit that raised my saddle a little - interestingly that shifted my left-right balance from being consistently 48:52 to being 50:50
that's pretty cool that you are now measuring 50/50!
IMO, the best value for the money are the Magene meters. A complete crankset for less than the cost of the single sided meters (which I have had terrible luck with) is a huge value.
Yes, Assiomas & Stages L. Soon to include the Assioma Pro MX. As ever when using them keep the firmware up to date, install correctly, calibrate frequently especially with changing conditions. Oh, and only use ones that have passed the GPLama & DCRainmaker seal of approval. Simple really.
I have a duel sided stages and love it, works super well and it is fun to look at all the numbers. I just don't look as good as nerdy Oli doing it though 😢
dual power meter (if the extra money is affordable) would be the better choice, monitoring eventually disbalances / change of balance over the months/years …. which might be a sign for „health“ issue like stability of your back, some nerves
Average cyclist so bought an average power metre. A Power pod. Cheaper than most. Does a decent job and didn't break the budget.
Props for learning from your mistakes and having a frame pump 😄
Why single-sided? You get good spider powermeters for little more than a single-sided crank/pedal system. I am pretty happy with a Sigeyi - which has been demonstrated to be quite precise, is very easy to set up, and add little additional weight (in my setup, just 80gr, considering that 12gr for the cadence sensor can go). Bought it for 378 CHF...
I am not going to to be racing maybe the odd mass participation event or challenge ride with a local club. But I don’t need a power meter, but ooh would I like yes please. Just to geek out and have another column of data / numbers on the Excel spreadsheet I use to keep notes on my rides outside of the Garmin Connect and Strava apps.
I think power meters also struggle with the type of load. Gradients exert a more constant force through the cranks. Cycling on the flat can have larger dead spots in the crank revolution. In my experience different power meters measure or calculate these efforts in a different way. I would like to see a study into this.
A dual sides crank power meter is only choice for a person like me who was born with disability. It measures my effort quite well with about 64/36 L/R balance most of the time. I have no regret of buying this, it is worth every penny.
I got a 4iiii single sided 105 R7000 model, v3.0, from Merlin and it was £325- less my "Gold" discount and a further £25 off for loyalty points it was £250.... Looked weird on my Sora bike and to keep q-factor even I quickly opted to upgrade the whole drivetrain to 105 when CRC did them for £299... a nice wee nudge to a worthwhile drivetrain improvement and the power meter has been superb. Yes a dual power meter would be good but would have to be one of the newer Magenes (p505??).... never Shimano though, I follow GPLama!!
Kind of like dynos used to measure the hp and torque of your car or motorcycle. You cannot compare the results to the results done on another dyno and in different conditions. They can be used to measure modification gains or to brag to people who dont know much about dynos…
Exactly.
The exact precision of the power meter readings is less important in my opinion to the relative data against prior readings in addition to the "how do I feel" metric.
Having a power meter and your heart rate information data can really help you with your own calibration of understanding your efforts.
Whether or not the numbers are completely accurate does not really matter.
GCN Tech, Subscribed because your content is fantastic!
thanks! What other videos would you like us to make?
first thing to check is your cadence. if that comes from the PM and drops out thenyour power will be wrong. power uses cadence in its calculation. there's also drivetrain loss and mamu other causes not mentioned in the video
The important thing with ANY measuring tool isn't that they don't always match with other measuring devices, it's that they provide SOMETHING that we can use to measure our performance. This allows us to then use the "measurement" to develop a training plan and see improvement in the number we use as a measurement. This improvement should translate into faster riding, no matter what we're using.
Of course, this assumes you're only relying on one measurement tool. Anytime you try to take numbers from one device to use on another, you're definitely going to have to create what I call a "translation matrix" to ensure the tools can help you do what you're ultimately trying to do, which is become more fit and faster.
This is an important point, it's all about finding your benchmark 🙌
As long as it isn't a current Shimano PM, you should be fine. lol
Accuracy doesn't matter, consistency does!
This. Absolute value has little importance, it's the amount and direction of change that usually is what's useful to know.
Unless you have a road and gravel bike that you interchange for training sessions. My gravel bike reads 25 watts higher which is frustrating esp if you are tracking data.
Of course it does. Get on a trainer and ride at close to your FTP and then ride at 20w higher and see what happens. Training zones are the bedrock of cycling and if your being told to ride at X and you are riding at Y then you aren't going to get the most from your training.
I bought a stages left sided power meter in 2017 but I will upgrade to a double in next yr or two. It seems quite accurate when I compare it with my times and weight up climbs to others on strava . However I doubt my left/right balance is 50:50 so there will be some inaccuracy. I believe(but don't know) my left leg is weaker than my right so if anything it prob under-reads slightly than over-reads imo. However it is consistent so when my power goes up I get faster up climbs and I get fitter. So still is a great training tool imo.
I have a stages LH on my race bike (came with) and always figured my left side was the weaker one--I'm right legged on the whole, and my left knee is the achey one. I just upgraded to a Duo-shi setup, and go figure...I'm slightly biased with left stronger. I.e. results may not be as expected.
@@brannmacfinnchad9056 Good point! Yes funny how we perceive one leg as the stronger but it could well be the opposite. haha Will be good to know for sure though :)
Some simple research will show which brands are accurate and which ones aren't. The accurate brands are absolutely accurate to the stated +-1%.
cost.
yeah most of them cost more than my bike :D
Strong hightop game, respect.
I have Garmin XC200's (shimano spd's) and I calibrate them for each bike I use, typically every few rides. I have found that with the same crank length on different bikes, the calibration can be way different. Now this is very odd to me. All my bikes have a 175 crank length but the calibration is different each time. I typically do this in my garage before the ride but the temps do vary quite a bit in the garage. I have seen the power difference it shows on my Surly (steel tube bike) to be far lower than on my Giant (carbon fiber). Of course being the Giant is 19lbs and the Surly 38, that also makes a huge difference. So many different numbers and variables.
How did you determine the calibration is different on each bike?
My pice of advice I can give to everyone: don’t forget there is also a calibration mode on zwift. Use it.
My zwiftnumberes were for long way higher than my Dual 4iii and Dual Assioma. And I had a hard time on zwift when I figured that out😅
Overall my favourtie are the Assioma Duos, good price, super easy and userfriendly to install. And easy to switch between bikes.
I have a quarq, speedplay powerlink pedals and a kickr and they all agree with 3W.
(I had a powerhub in the past that was good and a Stages left-side only crank that i had issues with).
all within 3w is pretty good isn't it? considering that they are all measuring power from different areas. Happy with that?
@@gcntech yes very
My PM's from my own purchasing and experience. Fyi, I ride shimano groupset.
1) Power2max NgEco. - Consistent accuracy, very long battery life. Calibrates quickly. Paired with rotor 24mm cranks means it works with Shimano chainrings and bottom brackets. - HIGHLY recommended.
2) Tacx Neo trainer - accurate, no need to calibrate. Recommended
Note - Power2max and Neo agree with each other consistently 🙂 .
3) 4iii gen 2 left-side only. Accurate and non peaky. Strain guage died after 2 years which also happened to 3 friends and is unfortunately common with 4iiii, Sadly, I can't recommend it.
4) Pioneer left-side only - Difficult to calibrate, inaccurate, extremely peaky with occasional readings in the thousands of watts. NOT recommended.
A single sided power meter is great for what most people actually use power data for. I've had both single sided and dual sided meters over the years and single sided is affordable and gives you data to compare efforts and do structured training.
You made us sensitive 🔔 to Alex saying.. However!
How do you compare a power meter vs. a heart rate monitor. Is there a comparative formula?
Unfortunately rate of external work and total cardiac demand are quite different and don’t really correlate well.
Power is a "lead" indicator of effort wheras HR is a "lag" indicator. For training purposes, both have zones, however HR can be impacted by fitness, day to day health so is a bit more subjective.
Good video
I would get one if I could afford it. I enjoy getting into the data for fun when training ,even though I'm not fast or good and I'm never going to be.
If the accuracy is +/-1% and you're out putting 200W, then the more accurate hub meter after losses might be better. At least with the hub, you know which way the difference is.
I don't think enough thought has been given for this video. This video needs a clarification from manufacturers' respective engeneers.
My limited knowledge in physics gives power as:
P = | F × r | ⋅ ω
If the you change between cranksizes (r) without setting up your powermeter everytime the your power measurement will differ.
Even though I’ve a power-meter in my crank, in my commuter, I chose to cycle by heartrate on all other bikes.
They also cost around 5p to manufacture but retail at around £1000.
Err, they’re not £1,000. Single sided start about £300
30 years of riding ... don't have a PM, don't need a PM, will not get a PM. But still love the video ... good info.
I agree. For myself, I’d never really done any sport or even exercise until turning 40 so a power meter was a really good way to learn what different efforts felt like and how to pace.
Never felt the need for one. Cycled all the European classics, Alps, Pyrenees, Dolomites. No data no problem😂
My Stages single sided power meter shows similar data as my Wahoo KICKR smart trainer...