Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

You overpaid for your powertaps and p2m by the sound of it.

Also, Powertap, SRM, P2m (basically copy of SRM) have been around for years. They're proven, tested, pretty reliable and have decent local service partners.

I'll buy the Ford for £1000 vs. the Lada for £800 every day of the week.

I've run SRM and Powertap on the same bike and Powertap and P2M on the same bike. Why would I use any other PMs? Especially ones that might be less accurate, less reliable and battery drain, service where? Blah blah blah.

So you currently have four power meters? That must be a ball ache altering all their figures every time you upload to training peaks, or do you apply an error multiplier to each one to make sure your results from various rides are consistent? Or, I'd bet, you ignore the difference and get on with your life? In which case, of course Stages is fine. Carry on. Be happy.

Decent local service partners? Are you joking? Srm send away to Germany, power2max send away to Germany, powertap send to Paligap, get in the queue, wait for parts, argue about the bill and warranty cover. When I've had a problem with my stages, I've had a new one two days later.

You're joking right? I've got hours and and hours and hours of power data from years of training with power meters and as Ed says, at best your power meter is 2% accurate so your 2% left right swing makes no difference because that will be constant in you. As long as you're happy that you're only using power for training and not willy waving then it is constant in yourself.

SRM customer service simply isn't worthy of the name in Europe, in the US it's very good though- full service, warranty repair, for free as a gesture of good will, done and returned in under a week.

I send mine to their Colorado service centre, best to act as if Germany doesn't exist.

Correct, there's no need to alter the figures really. The difference in reading between them isn't different enough to bother doing it. The power2max reads highest, both are on the same crank arms, same bottom bracket and same rings. Then the stages, then the powertap, but that's always going to read lower than a crank based meter.

So take it that you're 2% inaccurate even if you were riding at threshold for an hour that's a difference of 14 watts across the range of that 2% that your power meter admits that it can be incorrect by. Then take into account that no one here is Sky, or anywhere near world tour and at best British 1st category riders that are riding while having a job or at uni or similar. You can manage your form and performance perfectly well from tss planning, and ctl/ atl management they are accurate enough for pretty much everyone.

I do get all that^, and quite honestly I have no need for a single power meter, let alone the fleet which I have. I do have one single sided power meter- a Vector S - which I bought as the only way I could get power on a vintage bike (Klein Criterium), in the back of my mind was the upgrade path to dual sided if I rode the Klein a lot though.

What I am getting at is why buy something you know to be a compromised design with no upgrade path to a proper design, when a proper power meter is so close on price that it's not a factor?

As I said, I don't need a power meter, but that doesn't mean I'll buy a bad one.

Double sided will be here Sept, then you can just buy the right one and you'll have dual sided. and then realise it gives you the same number....

Although that will be interesting to see if I start getting different readings if I put the right side on too, I doubt it but I'll wait and see.

Fwiw I have Stages, track powertap and p2m. I mostly agree with @Slack here - it may not be 100% accurate but it is a useful training tool.

I once did a side by side test with my track powertap and Stages (when I was still using omniums) during a rollers session. Powertap and Stages were ~10w apart ( which can be attributed to crank vs hub) all the way up to 20min powe. After that Stages crept up to +/-1% for vo2max and topped out at +/-5% for peak power.

Conclusion - it's fine for steady state riding and training - just don't expect it to give you lab-accurate race data or record your peak power accurately - not that any of you tester bedwetters care about that :)

I'm glad that the same conclusion that was reached 20 pages ago has been reached again

If you've bought Stages, you like Stages
If you haven't, you don't

Stages: the 'Spok of the PM world

Also worth noting that my second gen warranty replacement has worked without issue for 1.5 years and is by far the least fiddly and most robust of the 3 PM's I own.

Pretty much. I couldn't be arsed to quote an earlier, similar rant.

I sold on my wired SRM before requiring anything, I've generally got good service from Paligap (it's not a case of replacement when it's custom wheels) and the P2M hasn't required anything yet.

How many new Stages have you had?

I'm sure Scientific Coaching does local servicing. Local, UK I mean.

Mine went back to Germany for a new back plate and calibration. I don't think SC do anything heavyweight here.

I've had three, sold two because I upgraded cranks and wanted matching arms. I've had two warranty replacements on the gen 1 because of battery door issues but that's been fixed with the newer body style. I've also had two powertaps replaced under warranty and had a torque tube replaced outside of warranty, so they've been no more reliable. Also the older body sl, sl+ powertaps weren't all that, rubbish bearings, and I don't mean what's fitted I mean using tiny bearing races in the non drive side with practically no shielding so they need to be replaced constantly. Rubbish spoke bracing angles because of the massive hub shell with narrow flange spacing. So while they may give you numbers they don't build into very good wheels compared to a normal hub. You can add shit free hub body's and sealing to that list too.

And they want a million pounds to do anything.

If you're happy with the Stages, and you're happy with whatever error factors you're getting that's fine. Some people are not prepared to add (more) doubt to their measurements.

If it's such a novelty item for us amateurs, why pay 80%+ of the price for power to get one with issues? Why bother at all? Powercal are cheaper or use TRIMP or some other HR estimation.

All my PMs have been bought second hand and most have been cheaper than a new Stages unit anyway so the value argument doesn't even hold in my case.

Basically, we are now in circular argument territory. I won't be uses Stages, other people can make their own minds up.

As a track sprinter, 5% for peak power could be a massive difference so you're kind of shooting yourself in the foot here. It once again boils down to 'the particular rider being happy with x error margin at x price point'.

That sounds like you replaced half the powermeter though. :P

I don't use that bike for max power efforts - it's a winter bike. The shortest effort I will generally do on it is 5 mins... But generally it just get used for loads and loads of z2 or Z3 work.

If I want to measure peak power I will use the p2m on road or Powertap on the track.

Nah has the plastic back plate, battery and the sticker on the front

As Neil suggests it was spendy tho

Much cheaper and faster to send to Colorado, honestly avoid UK/Europe.