Mileage on strava... accurate or no?

Hi,

Just wondering if there was a way to get the mileage to Strava to be as accurate as possible? Did a group workout a few days ago, all around the same FTP’s and mileage varied from 16-30 miles.

I probably shouldn’t care but I’m a bit OCD when it comes to overestimating my mileage. Is there any way around this or am I better off running Zwift alongside TR and uploading the zwift ride to my Strava?

Cheers!

Group workout or any erg distance is measured based on flywheel rotation. If you use your big ring and small cog vs your small ring big cog, you’ll get wildly different distances for the same effort, Strava or not

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Ah, so if I used ERG mode on TR and don’t let Zwift control my smart trainer this is the most accurate way to get realistic miles?

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A bit more background info.

It’s all based on trainer wheel speed and the tire size entered into the TR app.

TR does not do a calculation like Zwift does. If you want different output from TR:

  • Alter your ERG gearing
  • Alter your tire size in the app
  • Use Zwift or another app in tandem like you mention.
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Would it be possible to work out the correct gearing on my bike to get the same consistent (and accurate) mileage every time?

Your mileage was zero - you didn’t move! :joy:
Seriously though mileage indoors is a made up number you can make it say anything you want. Meaningless to be honest.

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The only way it would be accurate is is you had a wheel on trainer and used a speed sensor in TR. While Zwift may be a closer estimate than TR, it is nowhere near real. There is so much drafting, no wind, and the ability to take downhill mountain hairpins at 40mph that take away from the accuracy.

The core issue is that the gearing while in ERG mode will give you the same distance per revolution whether you are rolling at 50% of FTP or 100% of FTP.

In reality, assume the same conditions outside, each of those will get you very different distances. So its not simple to make better when doing workouts of varied intensity, via TR info.

There is an open feature request for TR to add some level of speed and distance simulation to give better data, but we have no idea if TR will ever offer it.

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No, your gearing on erg will just end up giving speed (and thus, distance) as a function of cadence. So hard or easy it’s still just cadence.

If you are “used” to a given average power roughly meaning a speed for your normal terrain, you could adjust to match that but ultimately the result is meaningless.

Even using Zwift is meaningless as you could ride the flats or the climbs and see dramatically different results for the same effort.

But it would be accurate to some extent. If OP has a 200w for 60 minute protocol, doing Desert Flats would yield more miles than Alpe, but that would be the case IRL too. Today I had Mount Bear. It registered close to what I’d expect for that power and distance and elevation

Typically I do the flatter courses for the easier rides or ones with a lot of breaks and then the hillier ones for harder efforts.

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Same could be said for outside riding.

Many are putting TR’s distance and zwifts distance in the same bucket. That’s an insult to zwift. Two completely different discussions. Sure, we may have issues with zwifts calculation, but they are minor things.

We need a down thumb :-1:option in this forum.

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Yeah that comment made no sense, at least on Zwift if you are on a hillier route it will show the elevation which will explain the lesser miles.

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If you’re outside actually accumulating distance I’m guessing it’s pretty close.

There’s no mileage inside. Period.

It’s hours on the trainer.

mile•age mī′lĭj
n. Total length, extent, or distance measured or expressed in miles.

n. Total miles covered or traveled in a given time.

Again no such thing as trainer mileage.

Fight me :smile:

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Fairly inaccurate, given if you’re moving something isn’t quite right on a trainer.

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Yes there may be better estimates at some point - and Nate has indicated he’s interested in implementing an option to better estimate by calculating the effective distance traveled based on the power output. I’ve posted code on how to do this, but if you’d like to know an accurate estimate of your distance is to do the following:

  1. Take your average power for your ride
  2. Plug it in on the page below where it says " If you apply _____watts of power, you will ride at velocity ____ mph ."

If you really want to fiddle you weight and the bike’s weight you can (a 50 pound weight change will make less than a 0.5 MPH change typically at 200 watts since here we’re assuming a flat course.)

This will get you a good estimate of how far you would have traveled on a flat course with no wind - I did some comparisons between just using the average power vs calculating everything second by second for a interval heavy ride (Gendarme) and the difference was about 1% vs just using the average power.

As for why people might care to know an accurate distance - well for me, I’m participating in a team virtual multisport “race” around the globe (going a circumpolar route a little over 30,000 miles). The race lets you use indoor ride miles. For the spirit of the event I would like to have realistic distances - not just throwing it in the 53x11 and magically do 34 MPH at 90 RPM. There’s no prize money, but it’s nice knowing that collectively my team (made up of extended family members) has traveled 5,300 miles in the past few months. Many of those miles done running / walking etc, with some trainer miles contributing as well.

Race link: https://runsignup.com/Race/CHH/AnywhereAnyPlace/CircumpolarRaceAroundtheWorld

Or another way to think about it - you’re not using the “mileage” as something you train by, but as motivation to do your rides and perhaps a few extra ones…that motivation is what can make you faster.

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So then I can ride inside indefinitely and never replace any gear (chains, cassette, chainring,etc) right? Because there’s no miles on them.

Edit: I know I’m being facetious but I just don’t get the whole notion that “indoor miles don’t count.” Yes, trainers can be off and over-report. They can also be off and under-report, like mine. Saying emphatically that trainer miles don’t count is stupid in my opinion.

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Trainer miles definitely count. However, if you’re training by mileage rather than hours/time, you’re training in the dark ages.

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Agreed.

They don’t count for mileage.

Running your car up on the blocks undoubtably burns gas and oil and wears down some parts of the engine…You just aren’t going anywhere that’s all.

I get it. We all want a participation trophy. A Tron bike, virtual green jersey etc.

Trainers do lots of things and most of all make us faster.

But we don’t accrue mileage on them. Mileage is only outdoors.

I get it though. I play PC video games I’m no stranger to pretend achievement.

It’s a stupid idea? OK we see it differently, count your pretend mileage all you want. I’ll stay in my corner and smirk at “end of the year mileage” totals.

I’ll keep counting my real miles and you can keep acting like you’re better than everyone else up there on your high horse.

Must be tiring to get annoyed by other people’s riding.

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