Author Topic: Digital EPO  (Read 9172 times)

rogerzilla

  • When n+1 gets out of hand
Digital EPO
« on: 05 June, 2017, 08:31:03 pm »
This has been around for a few years but I only just found out about it.  It's a rather amusing concept. 

Since Strava (as Tigerrr has rightly pointed out) has ruined popular routes by turning them into leader-board sprints, some wag has come up with an web app that mucks about with your GPS tracks, heart rate, power etc (just enough so it's still all believable) before you upload them to Strava, making you look faster  ;D

Let's face it, given the other tricks people pull to get unrealistically fast times through a segment, the market deserves something like this.

Disclaimer: I've only ever recorded one ride on Strava, it was direct from my phone and I don't think 15mph for 30 miles (had to keep waiting for the rest of the group, and the first part was psyclepath) is going to set the world alight.  Looking at the climb into Hannington, I call BS on the leaders' times; I was on fixed and had to wait 3 mins at the top for everyone else.  I did 6.1mph.  The fastest time was allegedly 19.4mph.  I don't think Pantani could have done that, even doped up to the eyeballs.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Phil W

Re: Digital EPO
« Reply #1 on: 17 June, 2017, 02:39:47 pm »
There's a segment up through a local country park. Slightly uphill. Always has dog walkers, young kids on bike, and people walking along it. Plus two sets of bollards to negotiate.  The leader averaged 32mph up it apparently. I don't think so.

Kim

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Re: Digital EPO
« Reply #2 on: 17 June, 2017, 02:49:44 pm »
There's a segment up through a local country park. Slightly uphill. Always has dog walkers, young kids on bike, and people walking along it. Plus two sets of bollards to negotiate.  The leader averaged 32mph up it apparently. I don't think so.

Thing about paths like that is that they can be completely empty at night.  I've accidentally managed surprisingly good segment times because of that.

32mph uphill through bollards is still unrealistic, thobut.

LittleWheelsandBig

  • Whimsy Rider
Re: Digital EPO
« Reply #3 on: 17 June, 2017, 02:55:43 pm »
The fastest speeds for an uphill segment along my commute are in excess of 70kph, just about the speed a car might do, if it were noticeably breaking the speed limit. It is all meaningless, of course.
Wheel meet again, don't know where, don't know when...

Phil W

Re: Digital EPO
« Reply #4 on: 17 June, 2017, 03:11:06 pm »
There's a segment up through a local country park. Slightly uphill. Always has dog walkers, young kids on bike, and people walking along it. Plus two sets of bollards to negotiate.  The leader averaged 32mph up it apparently. I don't think so.

Thing about paths like that is that they can be completely empty at night.  I've accidentally managed surprisingly good segment times because of that.

32mph uphill through bollards is still unrealistic, thobut.

Except their ride is timed at lunchtime on a Sat. I think not, not even at night could they average that as you start from virtually standstill getting into the park so no entering the segment at above 30mph.

Kim

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Re: Digital EPO
« Reply #5 on: 17 June, 2017, 03:40:18 pm »
The fundamental flaw with the whole concept is that the more capable a cyclist is of achieving impressive speeds, the less likely they're going to waste time chasing silly Strava segments.

TBH, I mostly view segments in urban areas as a way of sarcastically geotagging certain stretches.  It can be quite pleasing to do a ride somewhere new, look at the list of segments and see how other people have named parts of the route.  The timings are pretty irrelevant.


Kim

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Re: Digital EPO
« Reply #7 on: 17 June, 2017, 03:53:13 pm »
Quote
Although he'd trained in the area extensively over the past couple of years, Gaimon had never had the time or inclination to focus on picking up the many Strava records. But when the few he'd picked up incidentally started falling to Thorsinn-Sassquatch, he began to wonder.

QED

LittleWheelsandBig

  • Whimsy Rider
Wheel meet again, don't know where, don't know when...

T42

  • Apprentice geezer
Re: Digital EPO
« Reply #9 on: 17 June, 2017, 04:03:48 pm »
I think I've got one GPS track on Strava. It showed something like 4 km less than my counter so I never used it again.

GPS tracks are a laugh anyway.  When I was striving like buggery up a hill on Sunday my eTrex showed 0 kph for around 50 metres.  I find that insulting.
I've dusted off all those old bottles and set them up straight

Kim

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Re: Digital EPO
« Reply #10 on: 17 June, 2017, 04:12:46 pm »
I think I've got one GPS track on Strava. It showed something like 4 km less than my counter so I never used it again.

That's about your equipment though, not Strava.  It's only as accurate as the data you give it.  Which means it's only ever going to be reliable enough for fun and graphpr0n.

For discussion of robust ways of measuring cyclists' achievements, see the various HAMR threads.


Quote
GPS tracks are a laugh anyway.  When I was striving like buggery up a hill on Sunday my eTrex showed 0 kph for around 50 metres.  I find that insulting.

Nature of the beast.  A GPS receiver will never register zero movement, because the satellites are always moving.  The fix will wibble around within the margin for error.  So, quite reasonably, devices like the eTrex filter out movement below a certain speed, because it's usually better for the speed to read zero at low speed than for the odometer to clock up spurious distance when you're stationary.  Depending on how you've got the track logging configured, this may or may not affect the track log.


rogerzilla

  • When n+1 gets out of hand
Re: Digital EPO
« Reply #11 on: 17 June, 2017, 04:17:45 pm »
One theory is that GPS wobbles can cause the spurious high speeds over very short segments.  However, the fact that the top riders have all given themselves massive willy-waving names like KEVIN IN THE HALL OF THE MOUNTAIN KING TEAM PEAK STORMERS suggests it's all quite deliberate.
Hard work sometimes pays off in the end, but laziness ALWAYS pays off NOW.

Samuel D

Re: Digital EPO
« Reply #12 on: 18 June, 2017, 01:43:10 pm »
I have legitimately done 48 km/h up a ~2.5–3.0 % gradient. I was following wheels at about three inches, but some monster several riders ahead was sustaining that speed without aid. There was a good tailwind.

Obviously Strava is full of nonsense, but it’s also full of very strong, local riders who wait for a helpful hurricane and pump out scary watts in a targeted short segment. It’s comfortable to imagine the leaderboards are full of cheaters, but the reality is that there are people who can climb literally three times faster than a slightly overweight, middle-aged audaxer on a fixie.

Kim

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Re: Digital EPO
« Reply #13 on: 18 June, 2017, 02:11:38 pm »
While I don't pay a lot of attention to segment times (mostly just my own on a handful of reference climbs where external factors are minimised, to gauge fitness), it occurs to me that I haven't actually come across one that's completely implausible.  I have no problem believing that a proper cyclist is three times faster than me uphill, and that's usually the sort of difference I'm seeing.

Maybe outright cheating is a regional thing?

Oh, it's cos I'm looking at the women's stats isn't it?  Stands to reason that the cheaters are mostly going to be men, or perhaps men cheating by masquerading as women, which will give believable cycling speeds.

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Digital EPO
« Reply #14 on: 18 June, 2017, 02:51:28 pm »
I'm not sure I agree that the people really interested in Strava segments are the people who are less capable of recording fast times (without digital aid). Seems to me there are loads of weekend warriors and hyped up commuters out to smash a segment at five times Kim or Cudzo speed. But Strava is funny altogether. I'm now being followed on Strava by someone who has ridden (and finished) several TCRs. Yes, I do know him personally, but what makes it funny is that one glance at my Strava profile shows that I... never post anything on it!
Riding a concrete path through the nebulous and chaotic future.

Samuel D

Re: Digital EPO
« Reply #15 on: 18 June, 2017, 03:13:09 pm »
I have no problem believing that a proper cyclist is three times faster than me uphill, and that's usually the sort of difference I'm seeing.

Right. Young racers with genetic luck and years of proper training can easily be twice as powerful as your typical cyclist of average talent and not so much as a heart-rate monitor. It so happens that such racers are usually also much lighter than average cyclists, with direct implications on climbing speed. Then add in the weather factor (it stands to reason that Strava leaderboards are heavily wind-assisted) and the fact that the top times are expressly targeted as opposed to incidentally traversed on a 50 km ride, as you might be doing on any given climb. A factor of three seems reasonable to me.

Re: Digital EPO
« Reply #16 on: 18 June, 2017, 09:20:24 pm »
...

TBH, I mostly view segments in urban areas as a way of sarcastically geotagging certain stretches.  It can be quite pleasing to do a ride somewhere new, look at the list of segments and see how other people have named parts of the route.  The timings are pretty irrelevant.

This would be the perfect opportunity to share this...a sequence of segments I inadvertently encountered recently...


Kim

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Re: Digital EPO
« Reply #17 on: 18 June, 2017, 09:24:11 pm »
 ;D

WTF is going on with the fonts, though?

LMT

Re: Digital EPO
« Reply #18 on: 18 June, 2017, 09:29:08 pm »
Digital EPO is flawed, you can see the peaks on the speed trace when analysing the segment to know if someone has doctored their ride.


Re: Digital EPO
« Reply #19 on: 18 June, 2017, 10:33:39 pm »
;D

WTF is going on with the fonts, though?

You don't like choco cookie ?  🤤

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Digital EPO
« Reply #20 on: 19 June, 2017, 09:48:21 am »
Which fonts? There are only normal fonts in R_nger's post – and an image not available box (tried pasting it into browser and it doesn't evenn exist). But (in other threads) I've noticed Andrew C's posts having oddly variable fonts; I've assumed from some pasting he's done.
Riding a concrete path through the nebulous and chaotic future.

Karla

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    • Lost Byway - around the world by bike
Re: Digital EPO
« Reply #21 on: 19 June, 2017, 09:51:29 am »
I have no problem believing that a proper cyclist is three times faster than me uphill, and that's usually the sort of difference I'm seeing.

Then add in the weather factor (it stands to reason that Strava leaderboards are heavily wind-assisted) and the fact that the top times are expressly targeted as opposed to incidentally traversed on a 50 km ride, as you might be doing on any given climb.

I confess that my first ever Strava activity was when we'd had strong winds in one direction for the past week.  I looked up all the segments near me that went in vaguely that direction, dug out the Etrex, soft-pedalled out and blasted back on each of them.  Result: a very funny-shaped ride with three or four KOMs.

rob

Re: Digital EPO
« Reply #22 on: 19 June, 2017, 10:07:01 am »
One theory is that GPS wobbles can cause the spurious high speeds over very short segments.  However, the fact that the top riders have all given themselves massive willy-waving names like KEVIN IN THE HALL OF THE MOUNTAIN KING TEAM PEAK STORMERS suggests it's all quite deliberate.

I recently noticed that you can add nicknames on the CTT website so your entry on the starts appears with "the wind" or "thighs of steel".   I only noticed because one of the muppets caught doping last year had done that.

There are now coaches offering their services to help you #smashthatsegment.    Meaningless all of it.....

Re: Digital EPO
« Reply #23 on: 19 June, 2017, 12:38:52 pm »
Digital EPO is flawed, you can see the peaks on the speed trace when analysing the segment to know if someone has doctored their ride.

That used to be true, the old version would just remove a trackpoint every so often and then shuffle up the timestamps accordingly, so an original track moving at a constant pace would be interpreted as "20kph, 20kph, 20kph, 40kph, 20kph, 20kph, 20kph, 20kph, 20kph, 40kph, 20kph, ..." and easy to spot.

The revised implementation does interpolation between the points to make the speed increase look consistent, that way it can still correlate to the peaks/troughs in the power/cadence/HR rates in the data, but it requires frequent data points (ideally one per second) otherwise the interpolated locations may be off the road (and easy to spot that way).

At one point in time (before they fixed Digital EPO) I was going to write a version that did the above (smoother modifications) but included a way of watermarking the resulting data in such a way that it was detectable by companies like Strava at some point in the future, i.e. change the least significant digit of the lat/lon values to be a checksum against the other digits. I'd wait for a while so lots of people were using it and then hand over the details to Strava/GC/etc so they could flag such rides en masse.
 
A device that logged cryptographically signed trackpoints would be nice.
"Yes please" said Squirrel "biscuits are our favourite things."

Re: Digital EPO
« Reply #24 on: 19 June, 2017, 04:32:04 pm »
Which fonts? There are only normal fonts in R_nger's post – and an image not available box (tried pasting it into browser and it doesn't evenn exist). But (in other threads) I've noticed Andrew C's posts having oddly variable fonts; I've assumed from some pasting he's done.

That's odd - how about this...