ERG lagging and weird HR readings

Two problems:

  1. I have an Elite Suito which I use in ERG mode, with an iPad Air 2. With my Assioma and Speedplay pedal power meters, it takes 2-3 seconds to settle into the power zone when I change cadence, and my power graph is fairly flat (with a bit of noise).

But last night I used my new bike which has a Quarq spider PM, and it now takes 10 seconds or more to settle into the power zone. The general power fluctuations are about the same as with the other PMs, provided I keep my cadence constant - any variation in cadence and the power goes up or down by 20-30 watts and takes ages to get back to where it should be. I calibrated both the turbo and PM before I started riding, but this seems to be more of a communication issue than a calibration one.

  1. I use a Coros Apex Pro watch for running/fitness tracking etc. The HR is fine, it sometimes under-reads on a hard effort but it’s fine. But when I use it to broadcast my HR to TR through my iPad, the HR reading is overwritten by the cadence reading. I thought it might be an issue with my Assioma, but the same thing happened with the Quarq I was using last night (although it seemed ok when I first started, then after I paused and restarted when I forgot to turn my fan on, and the HR dropped down to match the cadence again). HR readings are fine with my Wahoo Tickr Fit.

Can anyone help with either of these problems? TIA

The Suito is extremely laggy with ERG. My solution which isn’t actually a solution is to use resistance mode. I’m not sure what is going on with your cadence/ HRM thing perhaps will help you out with both issues.

Per #1, are you using EXACTLY the same gearing on your new bike as you were on your old bike?

  • If not, you are altering the flywheel speed which can impact the performance and reaction time of the trainer in ERG mode.

  • You mention both Assioma and Speedplay pedals, presumably this is on different bikes? Just trying to understand what’s hiding behind this info and if it might be an influence like gearing mentioned above might be.

  • You don’t mention which app you are using, but presumably this is the TR app? Have you confirmed the PowerMatch setting for these power meters? There are 4 settings and using a different one might lead to altered reaction times too.


Not the same gearing at all - Assiomas are on a gravel bike (40t chainring), Speedplays on a TT bike (50t chainring), Quarq on a road bike (44t chainring). All running the same cassette on the turbo in the same gear. I’ll try putting the Quarq bike in some other gears and see if it helps. But if that is the case, it seems odd to me that the highest and lowest gearing options worked well and the middle one worked worse. I might also try putting the Speedplays on the road bike and un-pairing the Quarq, to rule out the gearing issue (I can’t have 2 PMs paired can I?).

I’m using the TR app on the iPad. Haven’t checked Powermatch settings - I just paired things up and started riding. Having read that link you posted, I think it may have been disabled and the turbo is doing it’s own ERG adjustments. I’ll check tonight when I get out to the pain cave.

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I have the same combo, Elite Suito trainer and Quark DZero power meter. That doesn’t sound normal. People will say that the Suito is slower to react, but it isn’t that slow and variations shouldn’t be that large. Something is off.

Can you follow @mcneese.chad’s suggestions and report back?

Customizing those makes a huge difference. Some things like reaction time are a matter of personal taste.

OK, short story is you have LOTS of variables at play.

  • 3 different power meters (and I’d bet decent $$ they don’t all “match”). Also, if any of those pedal power meters is a single-sided version, you have a risk of unequal power data per side skewing results vs the Quarq that is total power (not to be confused with double-sided, because they are potentially different… but thast’s a different discussion).

  • 3 different drive sprocket sizes. Assuming you use the same rear sprocket on the cassette for each, you have a notable range between them. 40 to 50 max is enough I could see that altering the flywheel feel. The 44 slots between them of course.

  • It’s possible that the differences you get between each bike actually makes sense when you consider the use case for each one. Lower vs higher gear will translate similarly between the road and trainer. So, this may not be a “problem” depending on the goals you have for placing any of those bikes on the trainer.

  • But when you take the 3 gearing and power meters in the mix, I am not surprised there are differences and that they also not necessarily “make sense”. Power data deviation probability along with known gearing is not something to ignore.

On to possible comparisons:

  • If you want to see and/or capture data from 2 or more power devices, you may be able to pair them all in the single TR app/device and review the data while pedaling and viewing the Devices screen. I’ve done this for some quick ball park tests with two power meters and one trainer.

  • If that doesn’t work for you, you will need multiple apps and devices running. You can use the TR app/device for one and either a duplicate TR app/device or something like a head unit.

  • Rough comparisons can be done live in either case above, but keep in mind the potential power smoothing settings you have applied to each device, along with the need to be extra smooth and steady on the pedals to minimize variability. That’s why real data comparison relies on actual data file capture and comparison to properly understand if any differences exist.

Trying not to open a can of worms here… :smile:

I checked the power match setting for the Quarq and it was on 0.5, same as the other two. I turned it all the way up to 1 and it seems a lot better, much quicker to settle into a new interval but still maybe not quite as quick as the others.

I am curious to try fitting each of the pedal PMs to the Quarq crank and comparing them directly - sadly both the Assioma and Speedplay are left pedal only so I can’t do all 3 at once. My plan is to use them all for a bit and then pick a favourite - Speedplay has no gravel-friendly option, Quarq limits my crank choice, Assiomas aren’t Speedplays.