ON Streetview, the blue gridlines on the OS 1:50,000 are 1km apart. The contours are 10 m apart. Use these as a scalar by holding a clear plastic rule up to the screen.
If two adjacent contours are 50 m apart, its 20%. By the look of the map, the contours are less than 50 m apart.
I’ve put its details through the calculation and it’s just on the cusp of being a short Cat 3.
I'd assumed that using a map to measure & calculate the maximum gradient was possibly less accurate than GPS data (with a barometric altimeter). It's a technique worth looking at again, at least to test this assumption. Using a digital map might be a little more accurate as the pixels can be counted, but it is dependant on how accurately the map is plotted.
I've done some brief research on climb category's but they don't seem to be accurately defined. What calculation method / tool did you use?
beware though I`ve found that Garmin can overestimate gradient if trees overshadow but I`d certainly believe 25 % +
If you `like` horrid hills have you tried Asterton Bank, on west side Long Mynd?
http://shrophills.blogspot.co.uk/p/asterton-bank-long-mynd.html
Yes even with a barometric altimeter in order to calculate gradient a distance measurement is required from the GPS signal. My gradient calculations average over 4 GPS readings, which seems to give the best balance between over and under estimating, but it's not perfect. Plotting the gradient shows up any significant glitches and I can manually exclude the suspect reading. The data I have for this climb looks quite good (no sudden changes in gradient). My data for the "Binweston Ln Climb" has 5 gradient readings over the steepest 20m section which are: 20.8%, 25.4%, 27.3%, 26.2%, 24.2%
I've heard of Asterton Bank, it was not on route this trip but we'll give it a go sometime.
It looks like this one on Strava, which averages 11% for 2.4km but from hovering over the profile, seems to touch 23% in places:
https://www.strava.com/segments/727327
I've been avoiding Strava (could be a slippery slope), but that's an interesting feature, just pity it does not give the maximum gradient in the stats. Scrolling along the Strava chart it seems to have a 10m resolution on the distance scale and I found a reading of 24.1%. So, using Strava how do you find the hill that you are interested in?
Are there any other tools like Strava that give profiles of hills and maximum gradients?
Thanks.
