First venture into measuring power

space2ground1

Hi all,
I’ve got to the stage where I think having access to power data would be very useful and for me, enjoyable in planning training. Before Covid I kept an eye on it using a wattbike in the gym from time to time but without that facility I think it’d be good to have my own power meter at home and outside on the bike.

Does anyone have any up to date recommendations for someone like me who’s not going to need ultra accurate data but something that’s enough to follow FTP/power based training sessions?

The price of Garmin vectors is out of reach so I’m wondering if I should wait or go for something simpler or less well known. Asking with Black Friday on the horizon too in case there’s deals worth watching out for.

Thanks for the advice!

dahat

4iii single sided crank, these are reasonably priced and will serve every purpose you need.

Daroxtar

This^
My next unnecessary purchase

Danville

I too highly recommend the 4iiii single sided crank powermeter. €300 approx and well worth that.

Dual sided powermeter costing a minimum of €1,000 will tell you that your left leg is 2% stronger than your right one, so what?

In you’re not racing single sided is perfect for your needs.

Remember a powermeter is primarily a pacing tool, lots of YouTube videos about them.
Best of luck.

lennymc

i'd also buy a copy of racing and training with a power meter by Hunter Allen - as a lot of the value in a power meter comes from understanding what the numbers are telling you. It's 20 quid, but is worth it's weight in gold.

lennymc

Danville wrote: »

Remember a powermeter is primarily a pacing tool

I wouldn't agree - a power meter is a device that tells you what power you are putting out at a particular point in time, and transmits various data points - nothing more - nothing less. It's what you do with that data that allows you use it for the various training aspects of bike riding depending on your goals - be that a TT or a peak power, or V02 or whatever.

joey100

Danville wrote: »

Dual sided powermeter costing a minimum of €1,000 will tell you that your left leg is 2% stronger than your right one, so what?

.

Not entirely accurate. Dual sided can now be got for fair bit under 1000 euro, Favero assimo get great reviews, same as power2max and can get both closer to 600 euro.

Dual sided measures both sides, single side measures one side (usually left) and doubles. So your left leg might be 2% stronger at 80% effort, but 1% stronger at 100% effort and then 3% weaker at around 110% and that's all when your fresh. Will this track accurately when you start to fatigue? Will it still be the same % when your only starting to fatigue or will the gap widen as you get more and more tired, 3/4 hours into a spin? The big thing you need from a power meter is that it's consistent, single sided power meters just can't be as consistent as a dual sided.

But it's up to you what you want and how much you want to spend. I have both so I'm not saying you necessarily need dual sided but you do need to have an idea of why a dual sided is more consistent and accurate than a single side.

lennymc

the assioma pedals are probably the best power meter I have had (been with power for 10+ yrs). Have had hub, crank and pedals from various manufacturers. The big plus with the Favero is that they are easily swapped between bikes - and are available in single sided for about 400 quid iirc.

Daroxtar

joey100 wrote: »

Dual sided measures both sides, single side measures one side (usually left) and doubles. So your left leg might be 2% stronger at 80% effort, but 1% stronger at 100% effort and then 3% weaker at around 110% and that's all when your fresh. Will this track accurately when you start to fatigue? Will it still be the same % when your only starting to fatigue or will the gap widen as you get more and more tired, 3/4 hours into a spin? The big thing you need from a power meter is that it's consistent, single sided power meters just can't be as consistent as a dual sided.

Well you're not entirely right there. A single sided PM can be every bit as consistent as dual sided, it's your legs that can be inconsistent. Most studies tend to show very little variance between the two legs, especially at higher power. The biggest differences are usually at very low watts and slow cadence.
You are right though, consistency is paramount. No point having a PM that varies by 10% from one day to the next.

FWIW, Sky (amongst others) raced on single sided Stages PMs for years. If it's good enough for them then it's absolutely fine for 99% if the rest of us. That said, if someone wants dual sided then go ahead and get it.

and still ricky villa

+1 on pedal based meters.

I was lucky enough to win a set of Power Tap P1s and use them across 3 bikes.
Swapping around is a doddle if you don't let them seize.
I've dual sided but never used it after the first few months

lennymc

Daroxtar wrote: »

FWIW, Sky (amongst others) raced on single sided Stages PMs for years. If it's good enough for them then it's absolutely fine for 99% if the rest of us. That said, if someone wants dual sided then go ahead and get it.

Just on that, im sure there was a big wad of cash in there as well
Personally - I very rarely use the power meter during a race to look at power data - as there is so much not in my control in terms of required power to not be dropped. I might occasionally look at it when climbing as i question my life choices that have led to that point, normally just before I go boom!
TT is different tho, as you can use it to help stay at or about your planned power for the tt.

Paul_Mc1988

If you're going for single sided and cheap I'd go stages gen 3 or 4iii.

4Wii is +/- 1%
Stages is +/-1.5% but has ATC (active temperature control)

If you're brave enough go for one of these
https://youtu.be/y38dwJ4h-TY

Plastik

https://www.adverts.ie/other-bike-parts-accessories/powertap-pedals/21699016 Seems like a great deal for dual sided.

gn3dr

I'm toying with getting a power meter also. I do really like the idea of dual sided pedals especially with some of the data that the Garmin measures. What turn me off a little bit though is the Look only cleats. All my stuff is SPD SL. Also the reliability stories of the Garmin pedals when they were first out is a little concerning. Then there is the price...I just bought a Kicker Core so man maths for power meter isn't quite working out at the moment.

Then the problem with the single sided ones is swapping from bike to bike is a pain. My stuff is relatively old but in mint condition from when I previously cycled so my winter bike has a pre Hollowtech Dura Ace crankset (7700) - to get the single sided I'd need to buy a full crankset - which is further unnecessary cost. The Summer bike would be OK I think because that has Dura Ace 7800.

Decisions decisions. It's a pity there are no SPD SL power meter pedals.

space2ground1

Thanks for all the info. I’d be hoping to do some FTP tests and base my training plans on that for triathlon in 2021. I’m never going to be competitive but I enjoy the data side of things and I think it’d be useful to make sure the training sessions I do are worthwhile. It would also help make good use of a training programme with power as an option.

I’ll be using the same bike on the road and with a non smart tacx. If it went well I’d consider spending more money the year after possibly but I don’t want to fork out loads and realise that I didn’t really get much benefit from it.

Loads of food for thought so far. Cheers!

this.lad

Very interesting thread. I have a Giant TCR with the power meter built in to the pedals, only got it recently and had no ide this was on the bike when I bought it until I picked it up and the guy handed me a charging cable for it 🙈

Deadly bike and I'm knocking out some decent speeds on ot so I was thinking that if I had CF a bit of solid data it would be a shame not to use it to try to improve my progress.

I use strava and all that but this seems to be the next step, I cycle alone almost all the time and am prone to sauntering rather than pushing myself, I think this might give me a bit more motivation, I dont even have a speedometer at the minute.

Any advice on the best head unit to use along with it? Anyone use the NeosTrack ?

Not trying to hijack OPs thread, might fit in nicely here.

Paul_Mc1988

this.lad wrote: »

Very interesting thread. I have a Giant TCR with the power meter built in to the pedals, only got it recently and had no ide this was on the bike when I bought it until I picked it up and the guy handed me a charging cable for it 🙈

Deadly bike and I'm knocking out some decent speeds on ot so I was thinking that if I had CF a bit of solid data it would be a shame not to use it to try to improve my progress.

I use strava and all that but this seems to be the next step, I cycle alone almost all the time and am prone to sauntering rather than pushing myself, I think this might give me a bit more motivation, I dont even have a speedometer at the minute.

Any advice on the best head unit to use along with it? Anyone use the NeosTrack ?

Not trying to hijack OPs thread, might fit in nicely here.

Wahoo element bolt is a great head unit.

Macy0161

I have two 4iii's. But if I was buying now I'd most likely go for Assioma Duo's. When I got the first 4iii, there were still on BePro iirc, which were a bit more faff to swap iirc.

Similarly, I have a bolt, but if I was buying now I'd go Garmin 530 or 830.

paddydriver

Another recommendation for the 4iii non-drive side. Got mine from ProBikeKit - Ultegra. Was very reasonably priced and works well. Be careful on frame clearance - I have a Canyon Endurace and is literally half mm between the actual little power unit and my rear stay. Have seen people talk of having to install a shim to get the mm needed to clear the frame.

I too would go Assioma or Garmin Vector if they were SPD-SL - I just prefer not changing cleat system. Have read of a patent issue and possibly it opening up soon so that they will be able to go SPD-SL on next iterations, and also possible Shimano coming out with their own pedal based PM's soon when new Dura Ace/Ultegra group sets arrive.

Power data is interesting.. I don't study it very much, but that said it has been that kind of year. Hooks in well with the Garmin head units and gives lots of figures.

G1032

Macy0161 wrote: »

Similarly, I have a bolt, but if I was buying now I'd go Garmin 530 or 830.

Why?

Taxuser1

Assiomas all the way every day. Best by DC Rainmaker. Price, measurement, ease of use and swappAble between bikes. Works with look pedals. And if you crash, the pedal itself isn’t expensive to replace as the powermeter and shaft are separate. Can change the bearings every few years for small money

Macy0161

G1032 wrote: »

Why?

Better navigation. Turn by turn on the bolt is dependent on what software you map on. Using strava, you don't get turn by turn.

A few other things.. Availability of cheap accessories/ mounts, and with no power meter the bolts calorie algorithm is off the wall (this is important to me, may not matter to others/ most).

RedB

I just took delivery of a my first power meter (Stages) and I’m out of depth already. I can’t seem to connect with it properly.

Do I need a fancy head unit or can it connect via a mobile phone as the website suggests? The Stages app is only able to calibrate it and doesn’t facilitate any data upload.

I just tried using the Wahoo Phone app on a 400m test ride and that seems to capture data but how does that connect to the Stages-Link website?

The Stages Sync app doesn’t seem to work as my laptop hasn’t been able to connect with the meter directly. Should I continue trying this approach or should I be trying to get the data to Stages-Link via a phone app or a head unit?

07Lapierre

Yes you need a head unit. Garmin or wahoo. The stages app can display power in real time, but if you want to record the data, you need a head unit. The app is also used for updating the firmware.

nilhg

4iii 105 PM for €229 and Ultegra for €269 in Mantel's Black Friday sale,

https://www.mantel.com/ie/power-meters

space2ground1

nilhg wrote: »

4iii 105 PM for €229 and Ultegra for €269 in Mantel's Black Friday sale,

https://www.mantel.com/ie/power-meters

Thank you! I need a 170mm for 105 and that's out of stock. I've set up a notification. Hopefully I might find similar on Friday.

Yermander

space2ground1 wrote: »

Thank you! I need a 170mm for 105 and that's out of stock. I've set up a notification. Hopefully I might find similar on Friday.

I was browsing the link above, and seen that the 170mm crank is in stock, if you haven't found it elsewhere.

Diarmuid

I have a Power2Max and a 4iii left sided. If I was buying one tomorrow, I'd go with the 4iii. Price is unbelievably competitive. I got one for 250.
The readings are very consistent but as others have mentioned may not give the full picture. So if you are just using it on its own, you won't have to worry but if you have a mix of power meters on bikes you will have to calibrate the 4iii one.
I had to add 10% to adjust for the difference in my left/right balance. Fortunately the 4iii itself can be programmed using a phone to do the adjustment on the unit. After that it's transparent

Taxuser1

earlier this week I did a 20 minute test and to be absolutely sure i recorded the ride with my Assioma pedals using the Garmin and the wahoo as the main power source - 3% difference between power sources. absolutely great pedals now 4 years old. one bearing change.

JimmiesRustled

Just to play Devils advocate here. I know a lot of people are happy out with single sided power and that's great. If it works for you and is consistent that's all that matters.

For me anyway the issue was the inconsistency of one sided power. Due to a couple of bad injuries when I was younger I have a non-linear imbalance between left and right legs. I say non-linear as it might be 49/51 between Zone 1-2, 46/54 between zones 2-3, 44/56 between zones 3-4 and so on.

The issue I had wasn't the accuracy, it was the inconsistency in training between zones.

So take for example a threshold of 300 watts, so zone 4, which in the above example had a 12% difference between left/right leg. That would mean you're no longer training in zone 4. If the power meter is on your stronger leg you're at 336watts and if its on your weaker leg its 264 watts. But that 12% discrepancy only occurs in zone 4. If it was 12% across all zones it could be accounted for no issues.

I think in comparison to when Stages first came out, the power meter market is now filled with decent competition. 4iiii on sale at the moment in the above link for €225 I believe. I think these generally retail for €270. An FSA powerbox which gives total power is €500 or you can pick up a pedal based system for anywhere between €640 - €700. The other issue to consider is if going to power, do you have more than one bike? Changing a crank arm and moving it across can be a right pain.

Power meters are great tools but I see so many riders inflating numbers and inflating FTPs for bragging points. A 20 minute test where no 5 minute effort to deplete W' has been used and then the rider takes 100% of the 20 minute figure and uses it as their basis to train. Which in turn lead to workouts that you can't complete because your FTP is too high. The same with Ramp tests. These can suit certain athlete types but even over on the Trainerroad forum there are a tonne of people complaining about being unable to complete 3x20 sweet spot work which is generally down to the fact that they're doing 3x20 at threshold. I would encourage anyone looking at moving across to power based training to have a read of the book that Lenny linked to earlier.

I digress but I just wanted to put forward the counter point to single sided power.

space2ground1

Yermander wrote: »

I was browsing the link above, and seen that the 170mm crank is in stock, if you haven't found it elsewhere.

I missed the boat again it seems!




So much great advice here, thanks again. I have just one bike and a basic enough turbo. Finances wouldn't really let me stretch to a two side setup at the moment so this will just be a bit of a luxury. What I'm hoping to do with it is just use it to have a better sense that my training is worthwhile. I'll do the ftp and then get figures to base a few weeks on and then the ftp again. Really I just want to see that I'm training properly so that theres some tangible improvement.

I'm not, nor will I ever be competitive but I think I'd enjoy and be motivated by knowing that the 6 weeks work I did based on ftp has led to an increase and I know I'm better for it etc.

I'm fairly sure my numbers won't be anything worth bragging about to anyone else so it'll just be nice to confirm that the training I'll do is working.

I'm going to need a better Garmin for the bike too (the triathlon black hole for money.. exhibit A) as my Edge 25 hasn't got a power option. I could put my 735xt on a bracket but where's the fun in that?

With the budget tight, I think the Garmin Edge 130 Plus will be the weapon of choice.