How to know hill gradients ?
ridgeway_swiss
Posts: 146
Is there a way to find out the gradient of a hill ? Looked on Google maps but couldn't find anything. Just curious to know what i'm riding up so i can plan harder climbs, still finding the short sharps ones a killer !!!
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You can plan a route on Ridewithgps and view the gradient throughout the ride then select a specific section of the ride.
Generally it works okay but I've found it to be wildly inaccurate at times.0 -
If you use Strava and the Hill is a segment, that generally shows the average gradient.
My Wahoo ELEMNT Bolt also shows gradient if I click to that data page.0 -
Some mapping sites will let you see (eg: ride with GPS) but often climbs that are particularly steep will have signs at the bottom of the hill telling you the steepest gradient.0
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Difficult thing with it in this country is they rarely stay at the same gradient for more than 100 metres and can vary wildly. Averages don't always give you a good picture, I find strava to be good as you can drag the cursor up the gradient and see what it is at any point (as long as the segment creator's gps was half decent!)
Steep ones will kill you if you're new, you'll be going into the red just to get up them and you can only do that so many times before you really fatigue. It will get easier.0 -
My Garmin allegedly shows the gradient but it is way off, small hump near home it thinks is 8% and draggy uphills it thinks are downhills!0
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Craigus89 wrote:cld531c wrote:My Garmin allegedly shows the gradient but it is way off, small hump near home it thinks is 8% and draggy uphills it thinks are downhills!
It's bad GPS not your Garmin's fault.
No it's not. The garmin has an inbuilt barometer and does not determine gradient from gps.0 -
Yep - its one with the inbuilt barometer (1000). Turned that screen off now though as it is useless.0
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redvision wrote:
But it still relies on gps location to calculate the difference in altitude over distance travelled, no? So if you're on a steep hillside and the gps is bad and it is thinks you are bouncing up and down the hill side it is going to screw up the grade reading.
I may be wrong but that is my understanding of it.0 -
I don't know how good the source is but it seems to make sense.
https://galebernhardt.com/blogs/news/ho ... cent-grade0 -
Correct. Weather changes will also affect barometer readings.Craigus89 wrote:redvision wrote:
But it still relies on gps location to calculate the difference in altitude over distance travelled, no? So if you're on a steep hillside and the gps is bad and it is thinks you are bouncing up and down the hill side it is going to screw up the grade reading.
I may be wrong but that is my understanding of it.0 -
Strava will give gradient and also Wahoo Element Bolt. I have it as one of the data fields, it's a guide and interesting but exactly how accurate is open to debate. I find with the Bolt there is a slight delay so although you may be on the steepest part of a climb it might not indicate that until past it. Obviously using the Bolt doesn't prepare you in advance so if you go up an unknown route it doesn't let you know whats coming up(literally), just what you're on at that current time.
For advance notice check Strava segments etc.0 -
That link was helpful - Ionly bothered to put the speed sensor on recently after I had already turned off incline so may give it another chance.0
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The data used by Strava, Garmin, OS etc is too coarse to accurately establish the gradient of most hills in the UK (a long, steady alpine grade, out in the open for example, would be different). It's good enough for mapping, but not much use for cyclists.
I've often thought that a bike computer could/should have a spirit level function, most smartphones do, and it could be calibrated to 0 on a level surface, and providing the mount stays constant, it would provide a good record of the gradient changes during the climb, and wouldn't be relying on the horizontal element from the GPS.
The only accurate way to establish the gradient of a climb is to pay a surveyor, or get a friendly one, to go out and measure it.0 -
I don't know any gradients really - but I know where the bloody hard hills are. Other factors make such a difference anyway - wind direction and strength. State of the road. Where in the ride it comes (Tour mountains change between categories - it could be cat 1 at the start of a stage but HC at the end) what the road is immediately before it - downhill, flat, draggy climb.
So its impossible to compare like for like. I did study strava and identified a route that would give me a pretty accurate profile of a course I was racing in Spain once. Practiced it over and over. Got to the race and completely different.
So I'd not stress it too much.0 -
^ Agreed, particularly the last para!0
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I've been looking at using the level function on my phone (someone mentioned it above) so that may be an easy solution although looking at the scale it seems to broad to give any meaningful information but maybe i can find a better app for that not sure.
Also just to add my knowledge of how steep is a hill is very poor, never really taken notice notice of it as it wasn't important to know. Just would be nice to know every now and then what i've ridden up and if i can take on XXX climb without it killing me.
Was back in the UK a few weeks back and trundled through the Trough of Bowland, it was a tad steep for me but a lot of fun but i have no idea how steep, 5-6% or something ? Shorter than my usual climbs but that kick near the top :shock:0 -
PhilipPirrip wrote:You can plan a route on Ridewithgps and view the gradient throughout the ride then select a specific section of the ride.
Generally it works okay but I've found it to be wildly inaccurate at times.
I find RidewithGPS to very much underestimate the gradient of a climb.
Hills which appear unproblematic around 6-7% on RidewithGPS actually turn out to be over 10% when I ride them!
It's common for me to do 200-300 meters more climb then RidewithGPS tells me what I'll be doing, this is on a 50-60 mile ride.0 -
Harry-S wrote:I've often thought that a bike computer could/should have a spirit level function, most smartphones do, and it could be calibrated to 0 on a level surface, and providing the mount stays constant, it would provide a good record of the gradient changes during the climb, and wouldn't be relying on the horizontal element from the GPS.
The only accurate way to establish the gradient of a climb is to pay a surveyor, or get a friendly one, to go out and measure it.
Well, a good old-fashioned spirit level would work fine - if you're going at a constant speed in a straight line: otherwise the acceleration would throw it off.
It should, in theory, be possible to combine the sensor technology in modern phones - GPS, barometer, accelerometer, tilt - to give an accurate measurement, but I don't know if any apps actually do this in an intelligent way.
I know for a fact that Google maps and Strava have dodgy height field info on roads near me, including my favourite hill on my commute (It appears to think the road goes up an old quarry it runs past :shock: ) so I wouldn't trust that much.
One day recently I did stop and measure the gradient on my street, just out of curiosity. Using a spirit level app on my phone - which seems to be reasonably accurate - it turned out as 12%: I calculated that from the displayed angle mind you, I don't know if apps would give you the actual percentage gradient.0 -
A lot of the time, the ‘official’ gradients, on a particular stretch, include any downward bits, and you get a ‘skewed’ average gradient figure. Then you come to your “6% gradient” only to discover it’s got two big steps on it, one of which is over 17%, the other one is not far off. That’s always a shock:0
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Ridgeway Swiss wrote:Also just to add my knowledge of how steep is a hill is very poor, never really taken notice notice of it as it wasn't important to know. Just would be nice to know every now and then what i've ridden up and if i can take on XXX climb without it killing me.
Assuming that you live in Switzerland, that does seem rather strange. I would have thought that it is pretty essential to know how steep the gradients are when you plan a ride and you should easily be able to gauge how steep a particular climb is because you ride so many of them. At least I do.
Unless you spend all of your time riding around the Zürisee or something!
Maybe this site could help, quite a few Swiss climbs listed here
http://www.quaeldich.de/paesse/0 -
mrdsgs wrote:
I already had the doogal segment explorer in my faves, but that link in superb... Plot your course and let it calculate the elevation, if you then suspect there is an unmade categorised climb segment, hold down left mouse over the gradient chart section you're curious about and it will tell you if it's a cat4 climb etc.
For those of you that know Clanfield near Butser Hill, earlier I discovered Petersfield Lane from Clanfield end up to the top of Hoggs Lodge Lane is a cat4 on doogal's tool, so I made a segment from Sunday's ride.================
2020 Voodoo Marasa
2017 Cube Attain GTC Pro Disc 2016
2016 Voodoo Wazoo0 -
A quick check of my commute shows that this has the same inaccurate height data as every other online mapping service.NitrousOxide wrote:mrdsgs wrote:
I already had the doogal segment explorer in my faves, but that link in superb... Plot your course and let it calculate the elevation, if you then suspect there is an unmade categorised climb segment, hold down left mouse over the gradient chart section you're curious about and it will tell you if it's a cat4 climb etc.
For those of you that know Clanfield near Butser Hill, earlier I discovered Petersfield Lane from Clanfield end up to the top of Hoggs Lodge Lane is a cat4 on doogal's tool, so I made a segment from Sunday's ride.0 -
Have you tried www.veloviewer.com ?
It's a great site for giving you every little detail that you need about the climb.
If you type in veloviewer and then the climb name in to google it should bring the page up. It obviously has all main climbs in the UK bit I've found everything I've ever needed to look at on there too. For example there is a local climb to me called Holly Lane. I typed in "veloviewer holly lane" and although it brought up quite a few different holly lanes it was easy to find the one I wanted.
https://veloviewer.com/segment/4176258/ ... +Peat+Lane0 -
Thanks for that link, will give it a try.
The gradient is something integral to my Garmin screen 1, as I've found it being a thing I use often when pacing myself on a climb. Here in Austria, I find that it can ramp up pretty steep and I know my limits for a given %, so this is pretty useful info. Despite that, my edge 520 fails ~ 10% of the time where it will say 0% when in actual fact it is closer 15%, so I wish it was more accurate...0 -
This was an absolute bitch of a climb, in Staffordshire, which was on a route I was leading, on behalf of British Cycling, for a charity challenge ride, earlier this year. Officially ( on the roadside sign ) it was 13%. As you can probably tell, it was a lot steeper than that in parts. We reckoned it was over 25% for a fair bit, hence the reason loads of people walked / staggered / got carried up by the end. It’s not uncommon to find this sort of thing.0 -
I might be wrong, but I think in the UK a gradient on a road sign is the average gradient from the sign to the top of the hill. I can't find anything on the internet to back this up though. I did read something that at the top of the hill, the sign shows the worst gradient, so if you are about to drive down it you know the worst it will get.
So, Barhatch Lane (or Winterfold) near Cranleigh, I think the sign at the bottom says 21%. When you ride it, the start is very gentle, rising gently, then it actually drops down for about a 100 metres, and then you get into the real climb which gets steeper and steeper until near the top. I think the top part must be over 25%...
https://veloviewer.com/segments/55691740 -
That sounds about right.DaveP1 wrote:I might be wrong, but I think in the UK a gradient on a road sign is the average gradient from the sign to the top of the hill. I can't find anything on the internet to back this up though. I did read something that at the top of the hill, the sign shows the worst gradient, so if you are about to drive down it you know the worst it will get.
So, Barhatch Lane (or Winterfold) near Cranleigh, I think the sign at the bottom says 21%. When you ride it, the start is very gentle, rising gently, then it actually drops down for about a 100 metres, and then you get into the real climb which gets steeper and steeper until near the top. I think the top part must be over 25%...
https://veloviewer.com/segments/55691740 -
SurferCyclist wrote:Strava will give gradient and also Wahoo Element Bolt. I have it as one of the data fields, it's a guide and interesting but exactly how accurate is open to debate.
I cross check my ride data both from my Bolt and my PowerPod and even if they differ a bit, the differences are so small that they are irrelevant, so I assume the Bolt to be accurate!SurferCyclist wrote:I find with the Bolt there is a slight delay so although you may be on the steepest part of a climb it might not indicate that until past it
I find the same, but it gives you an elevation preview if you plan for a route previously, and it does it in 100 m segments. So even if it delays, you can predict what is ahead of you.
Regarding Strava and RWGPS, they both rely on maps database and are very inaccurate, sometimes they’re just a bit off, other times (most of them), they are WAY off.
For reference, there’s a route that I do a lot, it has 65 kms and for the same route, Strava indicates near 1300 m of elevation whereas Bolt indicates short of 900 m. Strava and RWGPS are always wrong towards the optimistic side of things!0
