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

So....does it drop out if you go for a normal ride around the countryside?

I found the wireless PM stuff the most flakey when on the turbo. When I used to turbo.

Here's one with no drop outs and the other with (at the 39 minute marker). The one that dropped out is the brand new Garmin 1000. My last session it was the other way around, the 800 dropped out but the 1000 didn't.

What recording setting is there to check? Smart recording is off on both. Records every 1 second.

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Don't know, haven't ridden outside this year... fair weather cyclist and all that. Would be harder to tell though given all the coasting in lumpy bumpy kent roads.

I'm pretty sure its just wireless interference due to indoors and the million other signals about causing occasional hiccups. Just wierd it's only started in the last month. Maybe I have some new mr robot type neighbours broadcasting stuff.

1s recording is right.

How long is that dropout for? Do you have WKO or something that shows you the actual values for that time period?

6 seconds

Pure zero power values.

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Cadence is also zero. Do you have a separate cadence sensor?

Where is the Speed value from? If the PM signal was stopped, speed should also be 0, unless it's from some other source?

If the PM signal was stopped, speed should also be 0

Rear wheel speed sensor or smart trainer can/will report speed. If anything, because the speed sensor is reporting, it shows that the head unit is probably doing what it is supposed to be doing and the PM is either not signaling or its signal is not being picked up.

Cadence is from the P2m.

Speed is from the smart turbo, a direto, which broadcasts its own power speed and cadence, but I have the garmin set to only pick up its speed and cadence. I think it prioritises the p2m's cadence over the turbo's, but I'm not 100% on that.

both speed and HR continue to be picked up during the drop out, so something is blocking the P2m's signal only. But only on the Garmin 1000. The 800 read those 8 seconds fine.

#rep

wanna test garmin vector 3?

Yeah sure. 1 year long term test, no probs.

If the new Easton Cinch power meter measures power using strain gauges in the BB spindle, how can it measure power output from only one side of the drivetrain? That's what the reviews say it does.

The right crank doesn't wind up the BB spindle, the load passes directly from crank to spider to chainring. If you measure torque by seeing how much the BB spindle twists, you're only measuring torque generated by the left crank.

Old people will remember Ergomo who did the same thing for Square taper/ISIS/Octalink. You can judge what a great idea that turned out to be by trying to load their web site today :)

The use of optical shaft encoders rather than strain gauges is interesting, because it relies on measuring time accurately which is potentially easier and more repeatable than measuring the output voltage of a Wheatstone bridge. It would be difficult to implement in a spider based power meter, but it could work well in a hub and might be cheaper, more reliable and more stable than PowerTap's torque tube strain gauges.

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Yep. True. I obviously need an early night...

Look/SRM pedal based power meter under test by Adam Hansen looks close to production.

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https://www.bikeradar.com/road/news/article/srm-keo-g-power-51999/

So just tried the Cyclops Hammer trainer, and discovered about 45-50 extra watts.
Previously I was using Stages single sided and had been thinking it was underreporting, looks like my left leg is about 25-30% weaker than my right.

Which makes sense, given that I do Taekwondo and my right leg is dominant.

Going to find a dual side power meter / watt bike to double check.

That is a huge disparity, I'd be very surprised if that was the case.

Powermeters in reporting different numbers shocker

Just a guess, but both are reporting within their claimed accuracy, just at the opposite ends.

Just a guess, but both are reporting within their claimed accuracy, just at the opposite ends.

If +3% on the Cyclops and -1.5% on the stages on the Stages adds up to 45W, @Acliff is training at about 1000W :)

Well he didn't say if it was a sprint or FTP sustained effort stuff :)

Isn't 1000W your FTP sustained effort?

banned

Sobs in to WKO

1000w tempo session.

Obviously not an accurate observation, but I compared a very similar workout a few days ago, avg HR at 160 for both, avg power last time was 170, today 217.

Similar time of day, similar food, similar sensations of effort.

Unless I’ve gained 47 watts in 4 days, I think there is a fairly hefty imbalance.

Out of curiosity I checked thigh diameter and the left is 1/2 inch less than the right.

A year or so ago my right leg had felt really weak, and it ended up being an impinged nerve, which got sorted in 48 hours by a magic voodoo osteopath.