Please critic my way of calculating accent / decent gradients...

72hundred

Hello,

I was looking to find a way on-line (for free!) of telling me what the gradients of my spins were in degrees/percentages.... but didn't find much.

So I came up with a way of working with the data that mapmyride gives for elevations in the .csv format (probably have too much time on my hands today! :rolleyes::o)

1) Firstly downloaded the .csv file and opened it with Excel.

2) Then -without altering the fields- used this formula for the degrees in field F4, and the extended down and graphed it:

=ROUND(DEGREES(SINH((B4-B3)/((A4-A3)*1000))),2)

and this one for percentages in H4:

=ROUND((B4-B3)/((A4-A3)*10),2)

Its not a bad way of doing it and you get very detailed info about everything that coming up (see attached image). Also it gives a very independent info on how hard an actual hill climb is! (BTW the test file attached runs from Ranelagh to Howth Head, taking the south accent and north decent).




Any thoughts/ideas/improvements?



72oo

Chips Lovell

If you want to find out the gradient of a climb, toporoute.com will do it for you.

Diarmuid

I don't really see the usefulness of the angle?

For the gradient I would use a similar formula but let Excel look after the handling of the percentage and rounding (=(B4-B3)/((A4-A3)*1000)) It's more consistent and clear to keep everything in meters.

Eoin D

72hundred wrote: »

Hello,

I was looking to find a way on-line (for free!) of telling me what the gradients of my spins were in degrees/percentages.... but didn't find much.

So I came up with a way of working with the data that mapmyride gives for elevations in the .csv format (probably have too much time on my hands today! :rolleyes::o)

1) Firstly downloaded the .csv file and opened it with Excel.

2) Then -without altering the fields- used this formula for the degrees in field F4, and the extended down and graphed it:

=ROUND(DEGREES(SINH((B4-B3)/((A4-A3)*1000))),2)

and this one for percentages in H4:

=ROUND((B4-B3)/((A4-A3)*10),2)

Its not a bad way of doing it and you get very detailed info about everything that coming up (see attached image). Also it gives a very independent info on how hard an actual hill climb is! (BTW the test file attached runs from Ranelagh to Howth Head, taking the south accent and north decent).




Any thoughts/ideas/improvements?



72oo

I'm not sure what you've done there exactly but typically you don't work out the slope of a hill from top to bottom. There's different methods, I can think of SL1085 which means you take the slope from a point 10% in to the hill and a point 85% into the hill. It gives a better average slope

I don't know if thats any help!!

72hundred

Eoin D wrote: »

I'm not sure what you've done there exactly but typically you don't work out the slope of a hill from top to bottom. There's different methods, I can think of SL1085 which means you take the slope from a point 10% in to the hill and a point 85% into the hill. It gives a better average slope

I don't know if thats any help!!

Yeah, I hadn't heard of SL1085 before. Cheers.

el tonto wrote: »

If you want to find out the gradient of a climb, toporoute.com will do it for you.

Thanks for that link, didn't come across it during Googling!
Had a look at the website but is seems a bit hard to use, I tried to work out the north Howth road, so plotted a track around the head. But the mean grade came out as zero - I'm guessing the accent/decent cancelled each other out. Trouble for me would be that I don't know where the climb starts on a lot of my spins, (usually I just pick a route the night before on google maps), so I don't know how I'd work it.

Diarmuid wrote: »

I don't really see the usefulness of the angle?

Just another measure... I guess percentage gradients are the most commonly used.


I'll see if I can tweak it a little more.
Cheers for all the suggestions!!

Chips Lovell

72hundred wrote: »

Thanks for that link, didn't come across it during Googling! Had a look at the website but is seems a bit hard to use, I tried to work out the north Howth road, so plotted a track around the head. But the mean grade came out as zero - I'm guessing the accent/decent cancelled each other out. Trouble for me would be that I don't know where the climb starts on a lot of my spins, (usually I just pick a route the night before on google maps), so I don't know how I'd work it.

Yep, it will average out descent and ascent.

If you don't know the road well, clicking on the terrain view of the map will give you a good idea as to where a climb starts or finishes.

To be honest, I don't set too much store on the numbers any more regarding climbs. When I started cycling I used to spend ages plotting out gradients on various climbs to try and suss out how hard they are. What I've learnt is that the numbers only give you a very rough guide as to difficulty. On paper one climb can appear harder than an other, but in reality it might be a steady rise whereas the other one would be a series of short steep kicks up. You only really find this stuff out by riding them.

72hundred

el tonto wrote: »

To be honest, I don't set too much store on the numbers any more regarding climbs. When I started cycling I used to spend ages plotting out gradients on various climbs to try and suss out how hard they are. What I've learnt is that the numbers only give you a very rough guide as to difficulty. On paper one climb can appear harder than an other, but in reality it might be a steady rise whereas the other one would be a series of short steep kicks up. You only really find this stuff out by riding them.

Yeah I'm of that mind myself, I just like to play around with the info and see what can be throw out for the craic . The other major thing that no google maps or anything will ever be able to do - potholes/road surface! IMHO a very rough road surface makes any climbs twice as bad!

72oo

Chips Lovell

72hundred wrote: »

The other major thing that no google maps or anything will ever be able to do - potholes/road surface! IMHO a very rough road surface makes any climbs twice as bad!

Good point. It's something I really notice when I go to Spain. There are much bigger climbs over there, but they're made that bit easier because the roads are usually very good. Makes an even bigger difference on the descents too.

311

I'm not trying to pull a sale here ,but I have a polar S710 I don't use anymore. I could do a good deal for someone who would use it.

http://www.mtbr.com/cat/accessories/heart-rate-monitor/polar/s710/PRD_359794_125crx.aspx

Speed sensor might need a magnet.

72hundred

Alrite had a quick look over the thingy and got rid of the non-needed parts: angle, and a few mistakes in the formulas etc.

Instead now just a simple percentage
= Difference in elevation / TRUE horizontal distance * 100

{=ROUND((B5-B4)/SQRT((((A5-A4)*1000)^2)-((B5-B4)^2))*100,2) where B5-B4 is the elevation change and A5-A4 is the TRUE horizontal distance}

So climbing 1m in 100m's would be 1% etc etc.

I had to use some old trig knowledge to make up the formula, so it could be a load of bo^^ix :rolleyes:. But I think its handier now, and gives a slight indication of what the hill might be like. Only slight though given: road surface, wind, rain, accuracy of mapmyride.com, pints night before ....

Also the update interval between the points seems to be preset on mapmyride to 80 metres, so pretty detailed.

Again all comments welcome!



72oo