Distance and speed calculated incorrectly

Hi All

When my rides are synced to Garmin or Strava distance and speed are way off.

I know that this is an already discussed issue, I read several posts, but I am not happy with the explanations and this is to nudge further trainerroad to solve this issue.

As far I understood to fix this that would not be that difficult, give optional terrain or assume flat terrain, take speed, cadence, power, height, weight and give an estimate (instead just taking the free wheel speed).

Some other arguments:

  • “will the speed/distance this make me faster?” for me yes, since I compare total millage per week, and often I mix outdoors and indoors training. Then I would like to see how much I progress regardless of power. Then speed/millage are motivator. Instead when I see 25km/h for 250w avg I get demotivated :slight_smile:
  • I’ve seen much less sophisticated apps that can do that (eg. Elite workout app)
  • “keep it the correct ring”. I prefer keep it in the big ring with small cassette in the middle (the less noise), but even if I keep it in the highest gear it still underestimates.


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Maybe this is your answer.

Why would a sophisticated app like TR, who base their whole product on power, offer a guesstimate value for something that can’t be accurately calculated and doesn’t matter either?

I’d rather see increase in my performance based on power which is more important to progress and actually measurable.


Thanks for consideration but if I can give more explanations why this does not solve my problem.

  • trainnerroad already calculates something and does it very incorrectly. It doesnt have to be perfect but they just did a poor job at moment, that’s all. I imagine that’s not their priority but for me it’s important.
  • as I tried to explain above, distance (and sometimes speed), makes me faster by providing me more analysis of my workload (not only power), weekly, monthly, yearly, especially when mixing comparisons with outside rides.
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But the ‘speed’ measured from a TR workout is a completely artificial construct based on a host of assumptions which may or may not be correct …whereas Power is absolute. I’m not sure how an attempt to attribute a Speed to a power-based workout is helping your analysis…

I agree that if it’s something they offer, it should be as accurate as possible.

However, like you said, it’s likely not a huge concern of theirs since it offers little value when compared to power-based metrics.

A bit more info here:

Good luck :+1:

The article says they may add it in a similar fashion the OP is suggesting. I think the OP is just asking it be a priority. He’s not the only one.


Xert’s training system uses “speed from power” in their ios and android app and not the flywheels speed distance calculation. It assumes a flat road with some factors included for wind speed. For myself riding at 70% of ftp I get an average speed of about 18mph, which is pretty much spot on what I get IRL. Increases in my power output pretty much correlate correctly with my IRL speed on the flat.

I see in the wahoo kickr app there is an option to report speed from power - is this just when using the wahoo app or does it transfer to other apps?

Anyway, I agree with the others that tss would be a much better thing to look at rather than speed distance if you want to track progress. With that said I really do wish that trainerroad would automatically estimate tss for non-power meter rides…

Run Zwift alongside your TR workouts and upload only the Zwift rides to Strava.

However, the subscription cost might not be worth it if you use it only for this reason.

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There was a time TR removed speed and mileage from the software back in tbe early days. You could pair speed and cadence sensors to a head unit if the data is that important to you.

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Power (and TSS) is where it’s at to get quicker.

You’re on a trainer not moving with no air resistance, traffic etc - you haven’t moved any distance.

Funnily enough i’m using my old rollers at the mo with the PM on my bike to try to get some workouts done (trainer being repaired). Hilariously it shows power zones, time in those zones, HR and on Garmin Connect even though I could have gutted myself… Speed and distance - zero. So I could burn upwards of x hundred calories and move the bike forwards less than a couple of inches. Trying to compare that to how far i could have gone outside and at what speed. Why?

I’d rather not have virtual miles/speed - seems little/no point.

Plus you could influence this, depending on how it’s measured, by gear selection. Many use the small ring, others the big ring. …

Your total mileage on the turbo = 0 (maybe a few inches if you put a lot of effort in) don’t get hung up about it and use the consistent target of power instead.

Harder sessions for me will have a theoretical speed for me around 15mph but a lesser session will have a theoretical speed around 20mph+. The true metric power though will correctly indicate the first session was more intense/ a better work out.

Agreed. For clarity and direct reference, here is the official TR statement from the link:

Eventual Plans for TrainerRoad and Speed
TrainerRoad may eventually add a physics model that provides more reasonable estimations of speed indoors. However, this is not something that’s currently on our roadmap, so we don’t yet have an ETA for this feature.

So, they acknowledge the potential use and reason to take the calculation for Speed & Distance further. Nate has even asked if people would like to leverage that aspect for potential use in group rides and workouts. That is a whole new can of worms that we don’t need to debate here.

As mentioned, this is a Feature Request (as I have added the tag to the thread) and one that has been requested several times before. It is totally expected and desirable to use this and similar threads to “vote” for the request and to discuss the various merits for and against it.

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I thought a bit :slight_smile:

I think I still like my distance. It’s about power indeed but the question for me what I enjoy and get exited about. I know I am not perfect training machine yet :slight_smile: but again distance for me is an important motivator. When I do endurance ride, I care about power and time, but I am very proud of my distance, actually I enjoy it more. If I only ride indoors, then who cares but actually I prefer riding outdoors more. Sure riding on time under tension etc etc, but I also know the pain on 181st km on a long ride (regardless of power).

As discussed, I don’t think that it’s that difficult to fix it. All data is there anyhow, just change that formula.

If you ride in erg, distance has no meaning at all, as you can have low wattage and huge speed, or vice versa depending on the gearing and the breaking force of the trainer.


Wish it was 0. I normally get 0.2km or something stupidly small so analysis graphs do not work as all metrics shown against distance in Strava etc.

Been a while since we discussed this, but setting your wheel size to Zero (0) in the TR app might lead to zero speed and distance reported. I’m sure someone tried it, but don’t remember the results.

Additionally, if people want to manipulate the S&D output, they can tweak the wheel size to get data that is more to their liking. It’s a hack, and not offered as a solution, but it is all that possible right now.

In ERG mode, the speed(if I understand it right) is essentially just the speed/RPM of the flywheel on my Kickr Core, and doesn’t change with resistance. Workout is the same wattage whether I do 39x28 or 54x13, but the higher the gear, the faster the flywheel spins, and the “farther” and “faster” I go. I typically do mine in 39x19 or so, and the speed works out to about 28kph, or thereabouts.

Speed and distance are of course worthless metrics on a trainer. However, I do have a goal of 14,500 km I’d like to reach for the year, a carrot on a stick if you wheel, so I do like to get a reasonable distance value from a trainer workout, so that I give myself “credit” in a mileage sense for the time I put in.

I did ‘like’ that, but I don’t actually know how you’d use a speed sensor on a direct drive trainer.

Maybe attach it to the front wheel, that’ll give correct data for the workout… :stuck_out_tongue:

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  • Using an “old” magnet based design, use some adhesive to attach the magnet to the flywheel on the non-drivetrain side, and attach the pickup unit to your bike frame or the trainer (depends a lot on the locations of the related structures, and you would be all set.
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