Anomalous ascending numbers???

[Rob and Alison]

So, we each have a Garmin, one is an Edge 200 and one is a Garmin touring.

With LEJOG in this years schedule, we have started to look at our ascending numbers for the first time, but, what do we believe? Or what would be the best figure to go by? which machine, garmin connect or RidewithGPS,(Somehow we have clicked something which automatically loads each ride there too - operator ineptitude!)

For instance, Wednesday we rode 60miles and the numbers were:

on the 200 display - 727m
the 200 uploaded to Garmin connect - 452m
edge 200 on rwgps - 652m

touring display - 918m
touring on garmin connect - 496m
touring on rwgps - 937m

Being in Lincolnshire it isn't easy to route rides with a whole lot of ascent, but we would like to have an idea of the most accurate figure to help with planning training routes etc.

Thanks very much in advance for any help with this.

 

[Stephen Piper]

Maybe try manually loading the route(s) you ride into various route planning web sites, ie. Bike hike course creator, strava, garmin... there are a few, and see if the predicted ascents agree with any of the recorded figures. The GPS ascent record will be inaccurate but when uploaded to strava, for instance, the ascent is taken from known mapping points.

 

[Dogtrousers]

Just stick with one. They tend to be consistent even if they don't agree. And get to know which is higher and which is lower.

I tend to find that things that calculate elevation from maps tend to give lower readings than things that report totals from GPX tracks, and in turn this is lower than the reading on the trip computer of my Garmin.

I also find that Strava is meaner than RideWithGPS. (gives you lower elevations for the same upload).

So, for example, my personal benchmark is 1,000m in 100km as reported by RWGPS from an uploaded track. More than that is a significantly hilly ride.

• If I look at my planned route in RWGPS before I ride it, if it says 800 or 900 or so, I know it's going to be on or near the benchmark.
• My GPS trip computer when I ride it may be telling me 1100m of ascent.
• When I upload the track to RWGPS it may well tell me 1000m. This is what I use to compare rides with each other.
• When I upload the track to Strava it may well tell me 900m

If you want to compare rides (x was hillier than y) then always make sure you are using the same source for your elevation.

 

[Ajax Bay]

what would be the best figure to go by? which machine, garmin connect or RidewithGPS

RwGPS is best. GPS does not give good elevation figures and relying on any barometer reading (ie in the machine, if it has it) is not much better.

 

[Dogtrousers]

RwGPS is best. GPS does not give good elevation figures and relying on any barometer reading (ie in the machine, if it has it) is not much better.

Actually I do tend to find that the GPX derived figures (ie from elevations recorded by my GPS, not derived from mapping data) are very consistent. More so that I might expect. The same ride generally coming in to within 20m or so each time.

But I do agree that the most consistent thing to use is something that uses map data (eg a RWGPS planned route), as it should be the same each time. The only problem with this is that it's only as good as its baseline map data. But that shouldn't be a problem in the UK.

Just pick one, and stick with it.

 

[Pale Rider]

When I connect my basic Edge Touring to the Garmin website there is an elevation correction feature.

If that's enabled, it always brings down by quite a lot the climbing recorded by the gadget.

Seems to me there is also some 'vanity gradients' on the mapping sites.

I've seen numbers quoted for climbs which I know cannot be right.

For example the Strava segment for Ditchling Beacon reckons it peaks at more than 36 per cent and much of it is 20 per cent plus.

It isn't, the sharpest bit is under 20 per cent, nearer 16.

All I can think is the bloke who recorded the segment must have been pulling a wheelie all the way up.

Best advice is, as @Dogtrousers says, to pick one recording/data processing method and stick with it which will give you a reasonable comparison.

https://www.strava.com/segments/770191

 

[dim]

my Garmin Edge 1000 gives me the same elevations/very close to RideWithGps. However, Strava on my iphone calculates the elevations a lot less than RideWithGps and my Garmin Edge

there's always a question mark on the Strava page by the elevation of your ride.... click onto that, then it recalculates and the result is always a lot less that the Garmins (including my Garmin Edge 500)

 

[snorri]

Decisions decisions, I'm glad I did LEJOG in the olden days, it was so simple with just a few OS maps and a compass.

 

[dim]

Decisions decisions, I'm glad I did LEJOG in the olden days, it was so simple with just a few OS maps and a compass.

there's a saying: "If you use yesterday's technology today, you will be out of business tomorrow"

Garmin satnav has made cycling so much more pleasurable for me .... no stress about which turn to take, no stress about getting lost, no stress about cycling on roads / areas that I have never been on/to

I'd struggle with a map and a compass (I get lost in my own village)

 

[Banjo]

A ride I do consistently shows a 25% climb on RW GPS. The hill is only about 10% max .

 

[Dave 123]

I have a Garmin 810, my brother has a Garmin touring.

In the spring we cycled from Puerto Pollensa to Cap Formentor in Mallorca.

My 810 was accurate as to where we'd actually been, his touring showed he'd ridden a couple of miles over the sea.

Who knows!

 

[jay clock]

Don't fret - just do plenty of long rides with some hills and you will manage LEJOG fine

 

[PK99]

RwGPS is best. GPS does not give good elevation figures and relying on any barometer reading (ie in the machine, if it has it) is not much better.

Barometer reading is OK for short rides but home to home on a full day ride often shows me a couple of hundred feet higher or lower.

 

[Ajax Bay]

Barometer reading is OK for short rides but home to home on a full day ride often shows me a couple of hundred feet higher or lower.

That's because atmospheric pressure will not have changed much during a short ride but quite likely to have done so over a 'full day'.
Pressure (at low levels ie UK) reduces about 1.2% for every 100m higher (~1.2mB). You'll see atmospheric pressure shown in millibars on forecast charts. A change of one millibar would register as a gain/loss of height of >300ft.
When using a barometer/altimeter for walking/fell navigation, the procedure to avoid this anomaly is to re-zero (ie put the altimeter to the correct (as per map) height) every time a known height (eg a col) is passed.