working out a hill gradient? - This seems to work

I have been baffled why a hill I frequently ride up takes so much effort especially at a particular point. I have always believed it to be a 12% gradient but people on here say, that their ebike goes up such gradients with relative ease.

So I used google Street, as the camera, so I understand it, keeps level when taking pictures so I grabbed an image and then put it in google Sketchup and used the Protractor tool to ascertain the gradient at the particular point in the hill that seems harder.

Result?

[ATTACH]6137.vB[/ATTACH]

15%

It seems accurate because the rest of the hill comes in at between 11% and 12%

Try it, see what your local hill is.... if you don't have Sketchup (free download) just send me the co-ordinates of the hill you want and I will have a look for you.

You appear to have taken the photo at an angle to the hill so that may have introduced an error. Have a look at the photo below where I've taken it at right angles to the kerb but not at right angles to the handrail since the wall holding the rail is angled to the road. This hill has been precisely measured at 14% at this point so will give a comparison to yours:

http://www.flecc.co.uk/p/images/A1-Q%20on%20hill.jpg

This post of mine from 2007 gives an easy and precise way to measure percentages of gradients.

Here's a pic of the end of my 50 cm "measuring tool" based on a length of angle alloy strip:

http://www.flecc.co.uk/t/images/grad3.jpg

Have you tried the Mileage Predictor | Woosh e-bikes | electric bicycles sales & hire?

Click where you want to go, the tool uses google map data and works out gradient, power consumption etc. It displays a gradient chart and also includes a virtual ride using google street.

It's pretty accurate apparently.

Also; if you have an android phone, xclinometer is a free app which seems pretty good: Turns your phone into a measuring instrument.

But don't forget to pick-up your phone afterwards :o)

shucks.... did work (I think) 11.7% so yeah, it's a 12 percenter...

ah well getting up it now in 3rd gear + full power whereas 2 weeks ago 1st gear and full power so my legs are responding!

I'll be fit as a fiddle by the time I'm 103 !!