Hill gradients

[Ming the Merciless]

True. But speaking as a maths tutor (of adults), I can vouch for the fact that many people have a problem converting between fractions and percentages.

Indeed they might, maths literacy varies a great deal, and whilst I’ve done it here, there’s no need to convert when you see 1 in 3 or 1 in 5 or 1 in 7 etc. You just need to know what that means in terms of gearing to select before you hit it.

 

[Lovacott]

Thinking about it, I think the most universally comprehensible way of expressing gradient would be degrees, which would avoid all this fuss. But I'm not in charge, unfortunately.

I always express hills in degrees because I can picture 15 degrees, 30 degrees & 45 degrees etc.

 

[matticus]

You have experience of a 45 degree hill??

 

[Lovacott]

Your first sentence is correct. I think of it as short for "rising one foot in every ten" or whatever. However, your next is wrong. A 1 in 1 slope is 45 degrees - one upward for every one forward.

Yeah, one in and one up is indeed 45 degrees. My example would equate to 22.5 degrees. I just made a basic error in my example (I do this stuff in my job every day so don't show it to my boss, I'd get the sack).

 

[Ming the Merciless]

You have experience of a 45 degree hill??

Plenty of us do if you climb mountains. We even have experience of overhanging grades when rock climbing. How would they be expressed 110 degrees etc?

 

[iluvmybike]

Bigger the number the steeper the hill! Once the gradient gets to 15%+ then they are really really hard!!

 

[Ming the Merciless]

Bigger the number the steeper the hill! Once the gradient gets to 15%+ then they are really really hard!!

Unless it’s a 1 in n grade in which case the smaller n the steeper the hill.

 

[Blue Hills]

No there's no mapping, just a basic bike computer with GPS tracker.

ah, but on my etrex 20s it seems to be coming from the data on the device.
Reasons I say this:
If I download GPXs from some route planning sites they very often, along with the geog co-ordinates for each point, provide an elevation reading for each of them. I know this because I deliberately strip them all out using a text editor (I like my GPXs pared down).
All is well if I designate the file as a route, but if I delete this data from a file designated as a track, when the Etrex loads them it sits there for ages while telling me that it is importing elevation data from the device. Such is the Etrex's puny processor that this is a severe irritation and risks a crash, so I always keep the elevation data in on tracks.

 

[matticus]

Plenty of us do if you climb mountains. We even have experience of overhanging grades when rock climbing. How would they be expressed 110 degrees etc?

Yes all-right clever-clogs - but those slopes don't have road-signs on, do they?!?

And you're probably more interested in the hand-holds and crumbliness* than the gradient!

*Apologies to non-climbers for using this technical term.

 

[Lovacott]

Bigger the number the steeper the hill! Once the gradient gets to 15%+ then they are really really hard!!

I actually live near the top of a 20% hill which is the last bit of road I have to cycle up at the tail end of my 10 mile commute home.

Even in the "Granny Gear" I alight the bike outside my house with legs of jelly. That said, I see 20 year olds panting for breath just walking up it so I don't feel so bad by comparison.