Using GPS files as Audax qualification

[Phil W]

nobody cares because no one else loses out (barring annual points records) but somehow we are worried that people will be copying/modifying gpx tracks.

Im surprised nobody has yet mentioned the possibility that a cheat could gain a place at PBP dishonestly thus denying an honest rider a place.  In that scenario somebody honest does lose out.  Same applies to any other event that has pre qualifying criteria which is oversubscribed. 

That said, I don't see cheating as a significant issue in audax (based on c 20 years riding and 10 organising) in general we're an honest bunch which goes hand in hand with our "quietly bad ass" ethos.       

I thought we were discussing gpx validation of perms. Not relevant to BRMs as required to enter PBP

But surely relevant when discussing the propensity to cheat in Audax.  If someone is going to cheat I can’t see them limiting it to only DIYs. With PBP qualification rides there’s actually some kind of reward isn’t there?

[dynamo]

It's very easy to cheat on DIYs or perms. I wanted to compare the time that I'd ridden an audax to another person who'd ridden the same audax but in a different year so we weren't even on the same ride. I knew this other rider was competitive so I thought it'd be interesting to see how they'd done. I use Strava, so does the other rider but we weren't and still aren't following each other. So how to compare?

The other rider doesn't use Strava Flybys so that wasn't an option and of course I couldn't access their account to view their ride. Instead, I would look at a segment along that route, filter by date and then I'd find them. I could then see their ride via the segment view. Then I would download their gpx file using some software (used to be a plugin for firefox but there are other means). I would then stick this into a gpx modifier to give it some unique timestamps (so that Strava wouldn't recognise this as a duplicate ride) at the end of the ride where the rider had effectively finished, change the date to the same as my ride and then upload to Strava.

So after all that I would have two rides, both on the same date as my original ride and, that I could compare on Strava Flybys side by side effectively as if we were riding together.

You can obviously see how this method could also be used to present a fake ride as having been genuine.

But ultimately Audax achievements are ephemeral and there really is no point in cheating. There is no quantifiable benefit to riding audaxes above just going out for another bike ride. I find it really is about my experiences on that day. Riding audax is like setting personal targets for yourself such as reaching a body weight goal or cooking a newly discovered recipe.

[grams]

The one setting where perms do allow an advantage is the club championship. If you look at th leaderboard the only way to do well in that is to have riders who do shedloads of DIYs, since the 50% rule doesn't apply, and their points totals are well above what's practical from calendar events.

[frankly frankie]

You can obviously see how this method could also be used to present a fake ride as having been genuine.

But if more organisers made more effort like this:

...  I won't accept Strava files; unmediated gpx files only. ...

I've looked at the documentation on the website(s) which I'm sure used to say that the file submitted should be the 'raw' file and not a tidied up version, but the current documentation does not make this point strongly enough.

In practice there seems to be an irresistable impulse on the part of the rider to process the file in some way before submisson.  And yes I know that for many GPS users this is essential just to get a usable file at all.  But all this topping and tailing, and joining files that cross midnight, is unnecessary and unwanted - if raw data were the accepted norm, then any fabricated files would stick out like a sore thumb. 

As it is, organisers (have to) accept processed files so of course it's more difficult to spot a wrong'un, and the whole idea of using tracklogs for validation is compromised as a result.

[quixoticgeek]

In practice there seems to be an irresistable impulse on the part of the rider to process the file in some way before submisson.  And yes I know that for many GPS users this is essential just to get a usable file at all.  But all this topping and tailing, and joining files that cross midnight, is unnecessary and unwanted - if raw data were the accepted norm, then any fabricated files would stick out like a sore thumb. 

As it is, organisers (have to) accept processed files so of course it's more difficult to spot a wrong'un, and the whole idea of using tracklogs for validation is compromised as a result.

You have to do any processing? I just hit the "download gpx" button on strava, and it gets me a GPX, I sent this to the DIY Org.

I could send the .fit file that comes out the device I suppose. But with my Wahoo I've not had any need to do anything with a GPX to send it to the DIY org...

J

[Paul H]

Some of my usual DIY's use towns with railway stations I can get home from as controls, particularly the winter ones where there's a possibility of the weather turning unpleasant.  Seems it would have been a lot easier to fake them with paper PoP's than with a GPX file.  I could have done so without getting on a bike.

[Ajax Bay]

You have to do any processing? I just hit the "download gpx" button on strava, and it gets me a GPX, I sent this to the DIY Org.
I could send the .fit file that comes out the device I suppose. But with my Wahoo I've not had any need to do anything with a GPX to send it to the DIY org...

I send the .fit file from the Garmin directory/drive to the area DIY organiser (Tony). That is as unprocessed as it comes. Keep Strava out of the loop.
From the DIY FAQs [ https://www.audax.uk/about-audax/event-types/do-it-yourself-diy-events/diy-faqs/ ]:
FAQ11 What do I need to send in for GPS DIY validation?
We'd like the raw track(s) as recorded by the GPS. Please note:
    A single GPX file please (not .gbd, .fit, .tcx, whatever)
    Check that the submitted GPX file contains tracks relating to the current ride *only*
    Delete any extraneous track data (recording of travel to/from and about the start / finish, for example)

Our GPS track validation process requires a single gpx file. If the record of your ride is split across more than one GPS file and you have the 'tech', merge the tracks into a single gpx file for submission. Don't worry about joining the tracks; the GPS track segments are automatically merged when we process the file. If you don't have the 'tech to merge GPS files, send in what you have with an accompanying note and we will handle it.

Why is .fit not preferred? That's what downloads from my Garmin.

[Kim]

Presumably because GPX was well-established as the standard format before TCX and FIT came along, and is what the validation tools expect.  (GBD is a proprietary format that's only really used by the Garmin desktop tools.)  There's an marginal advantage^[1] to using the XML-based formats if things don't go smoothly.

Presumably your organiser is feeding them through a conversion tool, which is fair enough.  The increasing popularity of FIT probably makes this inevitable.  Bit more work for them.


_{[1] If your toolchain chokes on a GPX, you can at least look at it in a text editor and make a reasonable guess as to what might be broken, which is the sort of thing that makes no difference most of the time, but would naturally appeal to someone dealing with lots of GPX files from diverse origins.}

[FifeingEejit]

Insisting everyone riding a GPS validated audax uses a SPORT tracker (or similar) would be about the only way to avoid the file type problem.

The reality is, some of these devices aren't using FIT or GPX files nativley.

My backup device (cheap, crap not recommended but does the job as a backup) exposes no files over USB; the only method of extraction is via the phone app and even then the only way to get a file of it is to upload it to Strava and use their GPX download.

But... it cost me the whopping price of €40; and I've had to use a track obtained from it after cocking up on the Kazoo.

And on the Kazoo you only grab the FIT by USB if your WiFi is broken and have dropped your phone in the toilet, because it just does everything for you, modern interfacing FTW.

Start enforcing those antiquated GPX rules and either there will be a run on eTrex devices (seriously no need if you have a smart phone, the use case for a dedicated cycling GPS is pretty much down to battery life and ruggedness now) or GPS validation would be killed stone dead.

[tonyh]

Presumably your organiser is feeding them through a conversion tool, which is fair enough.  The increasing popularity of FIT probably makes this inevitable.  Bit more work for them.

Yes, yes (arguably), and yes.

[grimpeur du sudocrem]

We'd like the raw track(s) as recorded by the GPS. Please note:
    A single GPX file please (not .gbd, .fit, .tcx, whatever)

I wondered about this, as my Lezyne kicks out raw .fit files (as do many devices). The first few perms I did with GPS validation I sent both the raw .fit file and a GPX downloaded from Strava. But the Strava GPX files are enormous (one data point per second I think), so I just send the .fit file now, and no-one has complained so far.

The validation tool accepts .fit, so I suspect the FAQs for GPS may be a bit out of date. Or maybe it depends on the organiser. I keep meaning to ask Martin about it on one of his rides, but I usually forget because I'm busy having fun or stuffing my face.

[Paul H]

Insisting everyone riding a GPS validated audax uses a SPORT tracker (or similar) would be about the only way to avoid the file type problem.

I use a GPX Logger, this one
https://peterdean.co.uk/wpblog/?p=218

[FifeingEejit]

Insisting everyone riding a GPS validated audax uses a SPORT tracker (or similar) would be about the only way to avoid the file type problem.

I use a GPX Logger, this one
https://peterdean.co.uk/wpblog/?p=218

I meant SPOT not sport!

Reads as if that still has the intermediary file problem; with a tracker device that submits to a standard centralized service where the rider doesn't have access to tamper with the files.
It still has problems with impersonation (i.e. giving your mate the tracker and claiming their ride) of course.

[frankly frankie]

You have to do any processing? I just hit the "download gpx" button on strava, and it gets me a GPX, I sent this to the DIY Org.

I would call that a processed file.  Strava very possibly smooths the data, re-writes the elevations, etc etc.
But I do understand that for many people this is the only practical workflow now.

The validation tool accepts .fit, so I suspect the FAQs for GPS may be a bit out of date. Or maybe it depends on the organiser. I keep meaning to ask Martin about it on one of his rides, but I usually forget because I'm busy having fun or stuffing my face.

The thing about GPX is that it is an open, cross-platform, documented standard.  Other file formats are not.  FIT is very good (a big improvement on GPX in every way EXCEPT cross-compatibility) but it has evolved (and who knows, may evolve further) so that not all files with the extension .fit are equal.  This requires whoever is dealing with these files to have modern software kept well up to date, simply to be sure of being able to access the contained data.

To be picky, the AUK validation tool does not itself accept FIT (the software has not been updated in a very long time) but the file uploader does accept FIT and converts it to TCX which is a format the validation tool understands.  Unfortunately this conversion only works on older, un-evolved FIT files, and fails on files generated by newer Wahoo devices for example.  There is a note on the tracklog uploader form, that "Wahoo .FIT files may not convert correctly".

But I think this is by the way because, for various reasons, most organisers don't use the validation tool anyway.  Which again means that the whole process is compromised - because the tool does what it does very well (even if it could be a whole lot better), and I think it's highly unlikely that any organiser simply viewing a submitted tracklog on a map for example, will perform many of the essential background checks that the validation tool does.

Interesting reading that information in the FAQ - it contradicts itself really - it asks for a 'raw' file but then encourages topping and tailing, and joining files - all of which I think should be better avoided (though I'm not a DIY organiser).

[tonyh]

Thanks FF, that's considerably increased my insight into why things sometimes work and sometimes don't. Very useful.

But I think this is by the way because, for various reasons, most organisers don't use the validation tool anyway.  Which again means that the whole process is compromised - because the tool does what it does very well (even if it could be a whole lot better), and I think it's highly unlikely that any organiser simply viewing a submitted tracklog on a map for example, will perform many of the essential background checks that the validation tool does.

As an org who still tends to try the Validation Tool first, I'm glad to hear of its strengths.

[Manotea]

As an org who still tends to try the Validation Tool first, I'm glad to hear of its strengths.

Thus speaks the voice of hope over experience.

I use the original AUK GPX Validation tool for integrity checking and various other utilities for route/comparison checking.

The original GPX validation tool had some nifty features, for example automatically concatenating tracks and enabling subsets of the track to be selected. This removed the need to 'top and tail' and was also handy for isolating sections of the track for AAA review purposes.

The original GPX Validation tool was a remarkably well-considered piece of software and worked a treat. Alas, it fell behind when GMAP interface changed, by which time the developer had long since moved on.

[tonyh]

As an org who still tends to try the Validation Tool first, I'm glad to hear of its strengths.

Thus speaks the voice of hope over experience.

  The voice, also, of an ignorant wanderer in a complex land, who much appreciates the voices of The Ones With Knowledge!