Strange Data Gap

Last night I picked a 2hr 15 min Endurance workout. Started with ERG mode. About 30 mins in I planned to join a Zwift group ride (Tour de Zwift Stage 1). This worked out GREAT. During the TR workout, I went into DEVICES and “forgot” the Smart Trainer, and went into Zwift Pairing Screen and enabled CONTROLLABLE.

I could continue my TR workout, I could see my Power data (from my Pedals), and could keep the power at or above where TR wanted me to be. But I could also ride at-will and feel the Zwift gradients - shifting to manage candence.

Then after the Zwift ride, I reversed the control, re-paired the Smart Trainer with TR and turned back on ERG mode.

Anyway, while I know speed doesn’t matter… for some reason SPEED shows as ZERO during that Zwift Ride. Except TR knows my power data. I don’t know exactly how TR calculates a speed estimate, but it has to be based on a well-known power modeling formula Speed = f(power,weight), so just an FYI that this would be easy to “fix” if/when TR wants to fill in that gap in FIT data.

You could see if there’s anything in but I doubt they’ll have anything to fill such a large gap.

To fill such a large gap for free I think you would need to convert the file to a .tcx and edit it in a .tcx/ or word editor which would be a quite lengthy process. Folk might do it quicker with some sort of paid editor.

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TR doesn’t calculate speed, it comes from your trainer. So I guess switching the trainer to be controllable from Zwift meant it was no longer sending speed data to TR. Trainer speed as shown in TR is also just a function of cadence and gearing, doesn’t take W or kg into account at all. So spinning along at 150W at a high cadence and a high gear can give you a very high “speed” than laying down 300W in a lower gear/cadence.


Ok makes sense. The reason speed data is at least somewhat useful is that it helps track annual mileage. If speed data is at least somewhat close to IRL, then the equivalent total distance covered will also be at least in the ballpark when you look at your annual totals. TR could model speed using power. The physics are pretty well known for an equiv flat road, calm wind, riding on the hoods… for example. But def not a priority.

Sure, there is not a problem with “can it be done”. The issue is “should it be done” with respect to the massive list of other feature requests that TR has on hand.

Speed & Distance has come up a number of times and there are more than a few feature requests related to it. Nate has even touched on the potential for simple physics modeling. But they seem to have it well down on the “to-do list”.

For anyone wanting speed and distance for any reason, use of something like Zwift, RGT Cycling, etc. would be the best option at the moment.


Thx. Agree. And TR actually does a reasonable job with speed and distance when I do my normal TR workouts, with a reasonable cadence. It is just a corner case it seems when I turn off the Smart Trainer pairing. Cheers!

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