Can someone explain gradients % categories and elevation?

nuggiebok

I'm still a beginner so posting here

I've just started using Strava. I've been an endomondo girl for a few years for running and walking but since starting cycling I've wanted more from my data. I run a windows phone so use a third party app which talks to strava, seems pretty accurate.

As my distances are starting to increase (around the 35+plus miles now) I'm encountering hills. I've enjoyed them even though they have destroyed me. I've conquered each one and not had to stop at the top. Strava has made me really interested in the gradients % and elevation figures, but I don't know what it all means really. Most of my hills seem to be less than 0.7miles long at anywhere between 4-7%. How would this equate to the ratio gradient you see on road signs for example, 1:4?

Thanks

nuggiebok

Does the elevation depend on where you start relative to sea level? So if you start higher up, your elevation figure will be higher? Or is it purely the amount of feet you climbed in that ride?

sungod

http://www.1728.org/gradient.htm

ManxJ

1:4 is just 25%... so out of 100%... Anything like that is pretty much crazy steep. 4-7% gradients are nice little lumps and can be as hard as you wanna make them

FJS

nuggiebok wrote:

Does the elevation depend on where you start relative to sea level? So if you start higher up, your elevation figure will be higher? Or is it purely the amount of feet you climbed in that ride?

The elevation figure in Strava refers to the total amount of climbing you've done in a ride, not related to the elevation of your location relative to sea level. A ride over 2 small hills in Norfolk would give the same Strava elevation total as a ride over 2similar small hills in Nepal.

The individual segments have a bit more info, including actual elevation relative to sea level.

The summary percentage shown for a segment in Strava is the average gradient over the whole climb; 2% would be very gradual, 10% a very steep average. The road signs, like 1:4, or 25% (around here almost all road signs show % now, only a few very old rusty signs still have 1:4, 1:8, etc. is that different in different parts of the country?), often indicate the steepest bit of a climb, not the average over the whole climb. So a climb indicated as 1:4 (25%) on the road, could just have a 5% (1:20) average on strava with a short steep ramp halfway

Mikey23

somebody did provide a good explanation about strava hill percentages and how it relates to road signs a few days ago.. not sure where though!

i would regard an average for a ride of 100ft per mile as pretty hilly. dartmoor classic for instance has about 7000ft over 60 miles. ride london is 2500ft over 100 miles which suggests it is flat. my average over 2 years is 50ft per mile which is sort of average. i live in cornwall

welcome to the group and i hope your cycling prospers. strava is a brilliant tool

schweiz

Ratios converted to % and degrees (to 1 decimal place)....



1:1 = 1 unit (metres, yards, feet, whatever) up for every 1 unit forward
1:2 = 1 unit (metres, yards, feet, whatever) up for every 2 units forward
1:n = 1 unit (metres, yards, feet, whatever) up for every n units forward

owenlars

For simplicity gradient is the height you gain divided by the horizontal distance you travel. So 10 feet gained in 100 feet travelled is 1:10 or 10%.

Depending on how you have set up your app, elevation may be your height above sea level or the sum of the heights of all the hills that you have climbed. In the UK if elevation says anything over about 1000 feet it is probably measuring the latter as I think I am right in saying the highest road in the UK is only about 1500 feet above sea level and there are few roads higher than 1000 feet ASL.

ForumNewbie

I find that it gets really confusing when you talk about degrees, but the question is about percentages which is easier to understand, i.e. 20% means for every 100 feet travelled it rises 20 feet - a sign would either show 20% or 1:5.

You can see on Strava what the percentage is at various points on the ride, by moving the curser along the gradient profile, so even although the average for the segment might only be 4%, you will see higher percentages for the steeper bits.

nuggiebok

thank you all for replying. Makes a lot of sense now. Especially ForumNewbie when you said that Strava shows the 'average' gradient, as they felt a lot harder than that!

littledove44

nuggiebok wrote:

thank you all for replying. Makes a lot of sense now. Especially ForumNewbie when you said that Strava shows the 'average' gradient, as they felt a lot harder than that!

I always like to look at the Strava segments on veloviewer. It breaks them down into small pieces and shows more detail.

Here's an example. Strava says this segment is 6%. Veloviewer shows it as 6.4% but bits of it are much steeper at 15 to 20%.

nawty

Categories are a completely different matter. As far as I can find there isn't a specific way of categorising them but the number relates to the gear a (old) car would need to be in to make it up, I.e. The harder the climb the lower the gear/number. Don't know if that's true but I like the explanation.

neilo23

nawty wrote:

Categories are a completely different matter. As far as I can find there isn't a specific way of categorising them but the number relates to the gear a (old) car would need to be in to make it up, I.e. The harder the climb the lower the gear/number. Don't know if that's true but I like the explanation.

Just to add something:

Several factors contribute to the given category of a climb in a big race, one of which being the placing of the climb. A hard climb could be awarded a lower category if it's near the start of a stage as it would be considered harder after 150km of racing, and an easier climb a higher category if it comes at the end of a long stage.

FJS

nawty wrote:

Categories are a completely different matter. As far as I can find there isn't a specific way of categorising them but the number relates to the gear a (old) car would need to be in to make it up, I.e. The harder the climb the lower the gear/number. Don't know if that's true but I like the explanation.

I like it too, but it's a myth. A mountain pass in the Alps would be 1st category in a race, but you could get up it in a car in 3rd gear; a short steep ramp might only get 4th category in a race, but you might need 2nd gear in a car.

The categories used in races are determined by the race organiser, and they all use different criteria - there's no universal system.

The hill categories on Strava are purely based on total meters/feet climbed of the hill

Schoie81

nawty wrote:

Categories are a completely different matter. As far as I can find there isn't a specific way of categorising them but the number relates to the gear a (old) car would need to be in to make it up, I.e. The harder the climb the lower the gear/number. Don't know if that's true but I like the explanation.

That's nuts!! Surely?? There's a Cat 3 hill near here that my old car wouldn't have got up in 3rd gear and the car I had before wouldn't get up it in 2nd! OP - If you're talking about Strava categories, there is an explanation on the Stava website somewhere - I read it a long time ago. Pretty sure they're worked out by multiplying the average gradient ie. 8% by the length of the climb in metres ie. 1750m. This would give a figure of 14000. These are then split into the categories 4, 3, 2, 1 and HC with the lower figrues being in Cat 4 and the highest being in HC. I can't remember what figures the categories are split at, but that's how it works. So a Cat 3 climb could be steep but short, or not that steep, but very long.