Hill gradient

nick1972

How do you measure the gradient of a hill. I've been riding a few fairly steeps hills and would love to know what the gradient is

Sprool

get the free Strava app or similar gps device for your android or iPhone, ride up the hill then upload the data to the webpage. It will plot a graph and tell you the % gradient.

lc1981

Yes, plotting the route or riding it with something like Strava will give you an idea. It's not a 100 per cent accurate method though - I've found plenty of points on Strava where the gradient is wrong, in a way that suggests that the elevation data for the map is overlayed slightly wrong.

Peddle Up!

On a related point, is there a database or web site that gives the gradient profile of "cyclists' hills"?

kim10

Peddle Up! wrote:

On a related point, is there a database or web site that gives the gradient profile of "cyclists' hills"?

This might have some information. You can search per country:

http://www.climbbybike.com/

Bozman

Does Strava take an average rather than the steepest bit of the run? A few folk have pointed out up to a 6% difference on some marked climbs

Sprool

All it can do is take snapshots as you cycle along, say every 10 or 20 metres (IDK) to limit the amount of data stored/transmitted, so its going to be an average estimate, but it should give a general idea.

tiredofwhiners

There are two ways of measuring gradient as well - the old way and the Euro way.

One takes the height climbed divided by the distance travelled on the surface of the road, and the other takes the height climbed divided by the horizontal distance travelled.

So with the old triangle with sides A, B and C where A is the longest side, one way is A/B and the other is C/B

bartimaeus

Sprool wrote:

All it can do is take snapshots as you cycle along, say every 10 or 20 metres (IDK) to limit the amount of data stored/transmitted, so its going to be an average estimate, but it should give a general idea.

You can use this to get a better profile from the Strava segment. I think that Strava takes the profile information from whatever the GPS plot says when the segment is created - but then adjusts this based on mapping data. GPS only altitude data appears to me to be complete rubbish.

charlie_potatoes

bikehike mapping website gives the % gradient on hills. Also when mapping route it gives the total climb.
A great website. I use it all the time

farrina

Nick1972 wrote:

How do you measure the gradient of a hill. I've been riding a few fairly steeps hills and would love to know what the gradient is

If hill is particularly steep then the Ordnance Survey maps will show either single or double arrows thus (example is a Landranger 1:50,000 scale map)

http://www.streetmap.co.uk/idmap.srf?X=291500&Y=322500&A=Y&Z=120

Single arrow gradient 1:7 to 1:5
Two arrows gradient steeper than 1:5

If you were wondering what hill this is more here http://100hillsforgeorge.blogspot.co.uk/2012/03/hill-no-88-91-bwlch-y-groes.html

More here on map icons https://www.ordnancesurvey.co.uk/oswebsite/docs/legends/50k-raster-legend.pdf

Regards

Alan

noaddedsugar

Strava sounds good will give that a go!

When they talk about category climbs on TV coverage, how are they categorized ?
Is there a list somewhere I can hunt one down near me to train on?

paul968

I find mapmyride to work well. It is like bikehike but I find the interface somewhat easier to use.

http://www.mapmyride.com

Sprool

noaddedsugar wrote:

Strava sounds good will give that a go!

When they talk about category climbs on TV coverage, how are they categorized ?
Is there a list somewhere I can hunt one down near me to train on?

http://thecycleway.com/?p=32

charlie_potatoes

Sprool wrote:

http://thecycleway.com/?p=32

Thanks for posting that link Sprool.

Everyday is a school day

Bobbinogs

Ridewithgps is quite good, I prefer it to mapmyride but there are quite a few alternatives and a lot of it is down to personal preference. The shorter you plot, the more accurate the tools are as they average gradients due to limited granularity of source data. They are all close to real gradient and elevation climbed but do just give a guide when compared to contour counting or GPS tracking.

Pross

Charlie Potatoes wrote:

Sprool wrote:

http://thecycleway.com/?p=32

Thanks for posting that link Sprool.

Everyday is a school day

Unfortunately it isn't wholly accurate. The categorisation of climbs in the Tour depends on length, gradient, altitude, condition of road surface and position within a stage. Mountains sometimes get categorised differently from one year to the next. Other Grand Tours have a different classification system - the Giro has no 'beyond category' although effectively this means everything moves up a category and there are no 4th category climbs whilst the Vuelta has a 'high climb', first cat, second cat and third cat.

Other Tours just rate things relative to the toughest climb on the race so the hardest will usually be classed as 'first category' and then downwards. 1st cat climbs on the Tour of Britain would be 3rd or 4th cat climbs on the TdF and the lower ranked climbs here wouldn't get ranked at all.

drlodge

Measure either percentage or old way
1 in 10, is 10%...that's a fairly decent hill but achievable as long as you have the right gears
1 in 8 is about 12%
The steepest hills around me are 18% and 21%, that's about 1 in 5 at their steepest and pretty hard going!

Reane_Machine

paul968 wrote:

I find mapmyride to work well. It is like bikehike but I find the interface somewhat easier to use.

http://www.mapmyride.com

+1 for this.

Like the mapping and elevation features on there.

Tbh I haven't tried any of the others but i'm happy with MapMyRide.

It also tells you which category climbs are on there too and whereabouts on the route. More often than not they coincide with Strava segments, but it's good to know what you're coming up against!

I tackled my first Cat3 climb today - was well chuffed with myself until I remembered that there was still two Cat4s left on the ride and I was nearly completely shagged already.

ugo.santalucia

Bear in mind if a climb is not at least 1 mile long, any attempt to measure gradients will be affected by huge errors. As for all those 20-25% claims, most of them refer to sections of less than 20 mt, so not really significant... you will find that real climbs that average more than 10% over a mile are very rare even in hilly areas.
In the alps I am aware of a handful of climbs that average more than 10% over the all length and they are real "walls"

farrina

ugo.santalucia wrote:

As for all those 20-25% claims, most of them refer to sections of less than 20 mt, so not really significant

I think my lungs would beg to differ ..... and for climbs of 1:4 and steeper it becomes a battle to stop the front wheel lifting off the road as you pull on the bars.

Personally when I look at a climb I am interested in its maximum steepness, although quite rightly as you stated the average gradient (see example I gave above) and length in particular can have a major impact on whether you ascend the challenge (along with gearing of course ...)

Regards

Alan

g00se

Bartimaeus wrote:

Sprool wrote:

All it can do is take snapshots as you cycle along, say every 10 or 20 metres (IDK) to limit the amount of data stored/transmitted, so its going to be an average estimate, but it should give a general idea.

You can use this to get a better profile from the Strava segment. I think that Strava takes the profile information from whatever the GPS plot says when the segment is created - but then adjusts this based on mapping data. GPS only altitude data appears to me to be complete rubbish.

This uses the strava gradient data but adds extra analysis to the strava site:

http://veloviewer.com

Put in your strava ID, update on the various update page options, then click on a segment on the segment page.

g00se

g00se wrote:

Bartimaeus wrote:

Sprool wrote:

All it can do is take snapshots as you cycle along, say every 10 or 20 metres (IDK) to limit the amount of data stored/transmitted, so its going to be an average estimate, but it should give a general idea.

You can use this to get a better profile from the Strava segment. I think that Strava takes the profile information from whatever the GPS plot says when the segment is created - but then adjusts this based on mapping data. GPS only altitude data appears to me to be complete rubbish.

This uses the strava gradient data but adds extra analysis to the strava site:

http://veloviewer.com

Put in your strava ID, update on the various update page options, then click on a segment on the segment page.

Sorry - it uses the hobbart gradient mapping, but the colours are from strava - so if strava is out, the graph looks OK but the colouring is out.

dynoben

Hi, Ben from VeloViewer here. What colours should be used for what gradients? I can easily update the code to show whatever colours make sense.
Also, I wasn't sure what colours to use for the descending parts of a segment so just used darker versions of their uphill equivalents. Not sure it is enough of a contrast though to be obvious on the map.
The data does come from Strav but if it is out then you just need to raise a support call with Strava with the segment Id (or list of segment id's if you've got lots of them) and they will regenerate the elevation data for the segment for you. Instructions are on the veloviewer site at the top of your segment list page.

oleksiy

Here is another tool for strava segment gradient analysis. I hack it together it on my spare time
http://steepish.appspot.com/