Km calculation

The km calculation of latest systm (iOS iPad Pro) during workout is Not Correct.
After Workout and upped to strava its correct.


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Distance calculation on SYSTM and on SUF before that is at best, an approximation since the app is not a simulation of real world efforts.

That said, if you use the virtual speed option it does a pretty good and consistent estimate.

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You aren’t actually moving, so any speed calculation must be an approximation. SUF speed is fairly accurate compared to the speed you would travel outdoors with the same power output on a flat route with no wind.

But that also depends on whether you have a smart trainer, or a power meter vs a dumb trainer with virtual power, wheel on vs wheel off etc.

Too many variables, especially since you’ve not described anything about the workout you did, what actual differences you saw nor anything about your trainer.


Are you saying that the app reported value at the end of the workout changed in the app after it was uploaded to Strava?
Or that you got a silly number at the end of the workout in Systm and it’s still a silly number, but that Strava changed it to something more sensible after upload?

Just checking as the first option would be a bug, the second is usually as people don’t have ‘virtual speed’ selected.

I noticed this as well, I will be riding near by threshold one day and it says I am going 18 mph which seems reasonable then the next day I will be at the same power level and cadence on a different workout and it it will be 9 mph.

Check that you have virtual speed selected in the Devices tab. Sometimes it resets and SYSTM gets speed (and distance) directly from the trainer. When that happens in ERG mode, the speed and distance numbers are often nonsense because they are based on flywheel turns instead of in power.

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Thanks, I will check that.

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I think it was because the virtual ride. After disabling it (and taking from the wahoo snap Its the same)

So the Systm app in background is programmed to upload the non virtual speed calculated kilometers

Is there some way to prevent virtual speed from appearing in devices? I don’t know why it keeps appearing on my devices, but it did so again on me today. I am using systm on windows 10. I could turn off the virtual speed but it remained in my devices and the speed was switching rapidly between reading erg mode speed from the trainer(realistic speed) and virtual speed on the rotations. (I am really time crunched so I just switched the display off to avoid seizure inducing flashing as the display bar widened and narrowed between 300 kms per hour and 8.)

I am starting to wish systm had a setup for for dummies built into the app. This is minor, but is getting frustrating.

Right or left clicking on the virtual speed gave me no options to remove it. Where can I get virtual speed out of my profile/have it stop appearing out of nowhere?
There must be an obvious step I’m missing.

I think you have to deactivate it?

Virtual speed of 300km/hr? Virtual speed exists because ERG mode can cause inaccurate speed readings. That being the case, there’s likely another underlying problem that is affecting virtual speed. How are your sensors paired, BT or Ant?

I did have them paired via ant and BT at first. Am using exclusively BT now.

On my phone(android) this is also appearing, so it’s not specific to my PC setup.

@HeroQuest I would deactivate it but I am not seeing how to do that.

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you deactivate it by “selecting” (i.e. tapping on, clicking) trainer speed. By doing that you turn the trainer speed “on” (green) and the virtual speed “off” (clear).

You can’t remove virtual speed as an option. It’s baked into the app.

Edit: see pic. The trainer speed is selected and the virtual speed is deselected.

Edit 2: I reread your post @Isa and realize now you were turning it off already. Unless I misread my rereading :stuck_out_tongue: Can I ask why you don’t want to select virtual speed? I have found that it almost always gives much more realistic results. Final thought, do you really need to have speed displaying on your workout? Why not just turn the speed metric off?

Ok. That I had done, but the speed was still waffling quickly back and forth.
I checked quickly to see if it does the same today, if course it isn’t!
Yesterday settings appeared as this:

Would weak BT or BT interference affect only speed? Should affect all readings and not just speed if that’s the case, right?

Lol. It’s like taking your car in to a mechanic. The sound disappears and can’t be replicated until you take it home. :man_shrugging:t3:

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I don’t need speed. I actually dislike seeing it on my display as I find it distracting but:

I personally really love seeing the virtual distance traveled, even if obviously not true to life(I don’t know how to use virtual speed with a trainer plus erg mode? Thought it was just simpler to use the suito readings for all)

The speed display is more for my drop in audiences, who always want to know “How fast are you going?” or during the pro rides, “So, how fast are these guys going?” :joy:

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How about throwing your head unit on to display speed but keeping the metric off on SYSTM? You can track distance and speed on your head unit, be able to report it to your adoring fans and still not be bothered by the metric on SYSTM. Just a thought.

Edit: popping the head unit on will bring your fans closer to the action too. The sounds! The sights! The smells! :rofl: :rofl: :rofl:

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Haha, you overestimate my setup! My old sensor was just a $20 made in China speed sensor I only ever used with virtual rides.

At this point I time crunches prevent me doing enough outdoor cycling to justify a head unit… Or, can the indoor cycling justify it? Hmmm. Starting to sound like the N+1 rationale…

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I just notice this too.

Simply select virtual speed and the trainer speed will go clear. That is precisely what I do, and I am 99% using ERG mode. Even when not in ERG mode, I still keep it as virtual speed.

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