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

Exactly.

PowerTap's and SRM's are now quite established platforms- I've got a PowerControl 7, for example, which means* that 6 previous iterations of the design inform the present one.

The other advantage of PowerTap and SRM is that they are the only two (apart from maybe Polar) that have a total system- meter, monitor/head unti, and desktop software.

Garmins are infamous for fucking up Power meter output.

Also quite a bit of processing is done in SRMWin- I always download into that, then drag the export file into Device Agent.

*In theory

According to the research I did this morning, SRM's appear to be waterproof when immersed, briefly.

Garmins are infamous for fucking up Power meter output.

Why's that then? You'd think something as apparently advanced as a Garmin would be able to multiply torque by angular velocity a few times a second....

Rather than sending torque and cadence values for the Garmin to calculate, the Power2max apparently calculates the power itself and sends the values to the Garmin. Is it still prone to error in this case?

Only problem with the above is that, with no torque values being sent to the Garmin, you can't check torque values when hanging a known weight from your pedal... I think this makes it harder to check its slope.

evilbay

I must be checking at the wrong times, although the rarity is hardly surprising.

^^i don't know, basing this on the posts on the Wattage forum.

Recently I have had a 705 and a PC7 on my bars, they seem to say the same thing.

There were lots of 705s that messed power up, before Garmin updated firmware. I think Auto-Start was the main culprit for a lot of issues. I've always used my Garmin on Manual Start.

SRM is no longer functioning properly. Presumably because some of the dirt/leaves that have flicked up during the wet rides have moved the wired pickups enough that they no longer register. I'm growing rapidly tired of this piece of kit.

I never used my wired one in the rain, my wireless one has been used extensively in the pissing rain, flooded lanes and massive puddles, and has so far been fine.

It's not going to work tomorrow now.

I had a minor breakthrough with that stupid SRM this morning.

I'd pushed the power sensor out of the way during the weekend because it kept picking up dirt and crap and scraping on the crank and since the headunit kept turning off I figured there was no point using it.

Charged the headunit last night and put it back on and it worked with the sensor in the new position, further away!

So now there's no scraping due to it needing to be super close and picking up leaves and crap and the thing actually works!

http://www.youtube.com/watch?v=L03JVPaZpyc

In my experience you need to keep the PC-V head unit on charge all the time, I only used to unplug mine to put it on the bike.

I'm not seeing a lot of (read: any) positives with these SRMs. Maybe Power2Max is the way to go?

Depends really, do you subscribe to wattage?

Lots of info (read: bitching) about every power meter apart from the SRM there.

The positive aspect of the SRM is that the data is accurate, which seems to be a challenge for the other powermeters.

Quarq's suffer significant drift due to a) rain and b) temperature changes, which make them a great power meter for British use, for example.

My old wired SRM was no trouble at all, as long as I left the PC-V on charge.

My new wireless one is fantastic- zero problems (bar a dodgy sensor, but that was Bontragers fault).

I am going to get a P2M next, due to the cost- that'll be in the next few months.

We shall see.

I've submerged my SRM repeatedly over the last week, hasn't missed a beat.

It even reported power whilst pedalling through floods.

I might've subbed but I never read wattage unless something's pointed out to me.

TT forum throws up equal mix of hate for PT and SRM but both of these win over anything else. At least you can get them both serviced fairly quickly.

SRM wired is more accurate than wireless apparently.. but that of course requires that it actually works and the thing is charged and the stupid thing has been zero'd, blah blah. Wireless would probably be fine for me and the lack of stupid sensors would be great compared to the wired setup.

The whole idea was to trial one to see if it was worth moving to crank-based power so I could run a lighter, possibly faster, disc wheel. So far, I think I'll stick with 808+cover.

While the SRM head unit sat at home and the pickups collected all manner of tree leftovers, the PT ticked along just fine.

Well let me know if you decide that the SRM experiment is a failure- I'll happily take the kit off you rather than go for the untested P2M.

Did you see that SRM may make the PC-8 backwards compatible with the wired meters as they just won't die?

BTW have you suffered the torque tube failure that is widely reported on with regards to the Powertap?

PT went the other way with their G3s. The new hubs require new head units.
But that's because they moved away from proprietary wireless to ANT+ (which is a good thing I guess).

BTW have you suffered the torque tube failure that I'm am trying to make a big deal of with regards to the Powertap?

Yep, on a used wireless hub I bought from the US. It lasted me a year and then started reporting stupid values. Still cost me less than buying a new one.

I'm not trying to make a big deal about it- just gets reported on Wattage a fair amount, so I thought it would be a useful comparison to "real world" if you see what I mean.

I'm not trying to make a big deal about it- just gets reported on Wattage a fair amount, so I thought it would be a useful comparison to "real world" if you see what I mean.

300 posts mentioning "torque tube" on the wattage group in 10 years is "a fair amount"? Are you on SRMs payroll or something?

Without a comparison that's a useless metric, innit.

There are only 67 mentions of "Quarq drift", but that's seen as a problem.

Anyway, I'm not trying to knock the powertap- as you say, it's one of the most credible power meters out there.

Of course it's useless but so is your statement.

There are only 67 Quarq users, so it is a problem for them.

I bought the SRM to see if it was any better than PT. Even with PT's faults (most of which I reckon were caused by some dodgy apprentice doing the upgrade work and not sealing the hub properly) there's no reason for me to use SRM, other than standard disc wheels being cheaper than the £3k PT Zipp disc.

Why mention torque tube failures if you're not trying to knock PT? I'm running both and so far the PT works far better than the SRM. I might still plump for the wireless version but (new) P2M is looking like a better option or the lighter G3 hubs but they have the same problem of expensive disc option. Or ditch it all and go back to time splits like Wilko.

I mentioned the torque tube thing as it's the only widely reported problem with the PT- and I wondered whether this was a case of a few problems being reported loudly, distorting the "perceived problem", if that makes sense.

The Quarq temp/rain drift thing seems pretty unknown outside of Wattage (or at least I've not seen it in other places- you may have done so in the TT forums?)

Again with the "widely reported".. le zzz

I have no interest in Quarq. P2M only interest me because the simple ability to change batteries myself when I need to is far more important than 0.01% accuracy.