Incorrect distance

Hi, there were times yesterday I was doing 254 watts but only travelling 16.6km ph? With a cadence of 80.
Surely it means 16mph? How do I correct this? It’s syncing to Strava & Training Peaks incorrectly. Please don’t say distance doesn’t matter because it’s the speed that I need.

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Move into the big chainring :wink:


On a trainer the speed is not relevant. If you have a smart trainer and use a lower gear, the trainer has to apply more resistance to keep the flywheel going slowly which will give a low speed.

If you use a big gear, it will use less resistance and let the flywheel spin faster giving a much higher average speed. Look at Nate’s rides on strava, he is do 40kph at 220 watts on his trainer because he uses a very big gear and the trainer just adjusts for this.

If you aren’t using a smart trainer, then you can reduce the resistance level using the manual control which will kind of do the same thing. But again, speed and distance aren’t relevant on a trainer as it doesn’t translate to the road anyway, as it arguably doesn’t matter on the road either. It is all about effort, watts and duration always. You can always manually upload the equivalent distance that you think you would have covered on the road if you want.

And using a lower and higher resistance is about training what you want to train, lower resistance high speed is potentially better for time trialest, crit racers and high resistance low speed is going to be better for MTB riders, climbers and CX riders.


There should be some big flashing text before every ride and before entering the forum, that TR speed !== real life speed.




Speed doesn’t matter either.

Why is speed important to you? You will always struggle to get a “realistic” speed or distance on a trainer because you’ve eliminated most of the variables that would dictate these things


Could you elaborate on this? Are you following a speed- or distance-based plan?


You can’t compare zwift distance to TR distance. At least zwift uses science to get at least close. And the idea that you aren’t actually moving doesn’t make sense either. You are still burning the calories. Does running on a treadmill = no distance?


Absolutely. Running on a treadmill is duration not distance.

All indoor cycling is purely duration based and miles covered simply cant be taken seriously.


Hi Natasha and welcome to the forums :slightly_smiling_face: I took the liberty of googling your tri and aqua bike results :+1:

I would raise a support ticket with TR to resolve your problem, they may want to know what power meter and devices you’re using. You can use or do it from the app and it automatically adds the version of the software and devices you’re using.

As others have implied TR is only estimating the distance you might be travelling if you were doing the same effort outside. When you’re training to power, you’re only really interested in the watts you’re putting out relative to your FTP, and for how long you’re doing it.

Is the rest of your training distance based?


To clarify the cause of the inaccurate speed readings on ERG trainers, check out this excerpt from our Help Center:

Speed Readings and Smart Trainers

Speed readings taken from a smart trainer set in ERG mode are arguably the least reliable. Having a basic understanding of how ERG mode works will be useful before reading on.

Speed readings are not reliable in ERG mode because the trainer will automatically adjust the resistance to ensure the rider is matching their wattage target — regardless of their gear or speed.

For example, a rider could shift gears and/or increase their cadence to bring their speed from 20-40mph during an interval with a prescribed wattage of 250. In order to keep the rider at 250 watts, the smart trainer will automatically adjust the resistance to make up for the change in speed. This means the rider’s speed readings will indicate 40mph while their watts remain at 250. If the rider shifts back down to 20mph, the trainer will again adjust accordingly so they are still holding 250 watts.

(Incidentally, we recommend that you find a gearing/cadence that suits you and stick with it for the duration of your workouts in ERG mode. Shifting or drastically altering cadence can be disruptive to the workout as it takes the trainer several seconds to adjust.)

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The article Bryce posted probably covered this, but: this is absolutely not true. What TrainerRoad uses for “speed” is what your speed sensor reports. Your speed sensor is counting how fast your rear wheel is rotating. That is strictly determined by your cadence and gear. How much power that happens to take depends on the resistance in the trainer-bike system.

For a direct drive trainer, the speed sensor may be counting hub revolutions instead of wheel. In Erg mode, the resistance of the trainer is automatically adjusted. Otherwise, the same principles apply.


Okay, perhaps I’m in error here calling it an estimation. I don’t have a speed sensor, I have power pedals and smart trainer, but I would personally still say that counting revolutions is an estimation of how far you would ride outside on a real bike where other significant factors are at play.

Either way, I don’t think this undermines my main point.

Absolutely not.

As I mentioned, if you have a direct drive trainer, your “speed sensor” is integrated into the trainer and is counting revolutions of the internal mechanism attached to the bike drivetrain. (This is multiplied by a wheel circumference to yield speed.)

The speed is simply reporting what is happening mechanically. If that happens to be roughly the same number as how fast you would be going under some particular conditions outdoors for the same power, it is a coincidence. Neither the trainer nor TrainerRoad are doing any math to produce a speed number that is intended to “make sense” to you


I agree with what you are saying but I believe there are smart trainers that will attempt to estimate speed based on power output. But you are still correct in saying that TR is simply pushing that value through and is not doing any of its own modeling to to correct any speed or distance values.

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  • Yes, Wahoo offers a related setting. I am not aware of other brands with this setting, but they may also be out there.

Additional ERG Settings:

ERG Mode Speed Simulation: This setting simulates speed based on power input for greater accuracy of speed data. Enabling is a personal preference, will not impact overall trainer functionality, and not required (most who train with power are not concerned about speed data).

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I would only say that’s true when it comes to TR. Zwift at least has an algorithm in place to calculate speed based on w/kg, cda, and terrain, etc. There is no cheating the speed in zwift. You could purposely mess with calibration of trainer so it reports higher power, but you can’t cheat zwift speed calculations after the power is reported.

Although I now really just track power and duration, there was a time where I looked at speed and distance. And speed and distance were factors to motivate me to continue riding and to ride more. I hate the attitude behind that meme because it could demotivate some to ride. We need to do the opposite and motivate. I do find it funny it had zwift in the meme and not TR.

There were lots of folks who posted their Strava year summaries in a thread in the TR forums. All of them listed distance. All were impressive and highly motivating.


Thanks for everyone’s replies. I’m not sure what to think to be honest. Whenever I’ve gone on a treadmill I have always trained to 5km, or 10km. So always distance.
On a turbo trainer, always to 20km or 40km etc.
So I’m totally confused to why no one sees distance as relevant. I see this as a factor to your speed=distance/time.

I guess you can’t calculate the distance because it doesn’t in effect have a wheel. This frustrates me lol coz I’m so ruled by distance due to taking part in Ironman events.
Hmmm is this why when I sync my rides from Trainerroad to Strava the Avg speed is always way off?

But say I have to find out how fast I can do 40km to prep for an Olympic distance tri??