Playing with Garmin Tracks – GPX files, counting corners on a SaddleSore.

So today I posted this post up into the NZ Distance Riders Facebook page, and to the Iron Butt Riders group:

I was chatting with someone about Twisty SaddleSores, and being in New Zealand, I know that we always have to do a LOT of corners when we go on our LD rides.

So I grabbed the Garmin GPX track from our recent SantaSore1600K and imported it into Excel, then with some mathematical wizardry, calculated the bearing between each track point to the next, then figured out whether the bearing was increasing or decreasing. I made special considerations for those changes passing through ‘0-degrees’.

Then, by formula, I counted the number of times the ‘right or left’ changed – indicating a corner.

Does anyone want to guess how many corners we did on our recent 1600K ride? – I’ll even give you a SpotTrack reference for you to examine if you like? – https://spotwalla.com/tripViewer.php?id=212385e0e8a8440e08&hoursPast=0&showAll=yes

I’ll provide the answer to you in ~24hrs… 🙂

I told a few of the IBA guys that I’d share the spreadsheet, so here it is: TwistySore (XLSX) and (Zipped)…

So, for the three North Island SaddleSore rides I’ve analysed, two of them had around ~4,800 corners, and the twistiest one had ~5,300 – so that’s between 2.9 and 3.3 corners per km.

I then added in our 5,593kms from our 2019 South Island tour which included the TT2000 trip within it. Across that distance we did 19,528 bends. An average of 3.49 corners per km.

For ease of calculations I’d say that the NZ North Island is ~3 corners per km, and the NZ South Island is ~3.5 corners per km.