Sunday, October 21, 2012

Strava followup

I emailed Strava's customer support asking what the accuracy of a segment that short would be. Here's their response. The accuracy of very short segments depends entirely on the quality of the GPS hardware recording the data; however I can say that the shorter the segment, the more prone it will be to GPS errors. Most GPS devices have sampling rates anywhere from every 1 second to every 10 seconds. Clearly a ten second sampling rate is going to render a 5-second-long segment completely inoperable. Unfortunately there isn't really anything that can be done to improve the accuracy of the segment - other than encouraging your friends to get high quality GPS devices. I did some experimenting in a field during barrier practice where i set a lap marker on my garmin before and then after the barriers i set up. I had the auto lap feature but it was a total crap shoot as to when it would trigger a new lap. It was a difference of up to 20 feet. So long story short it might not be that reliable.

Sunday, October 14, 2012

Using Strava to analyze Cyclocross Technique

I don't use Strava on a regular basis but if I have a ride i did well on or a race i'll upload my file. After uploading my last cross race i had the thought of what if i created a segment that was just the barrier section, or in the case of the Psycho Cross race, a flyover. I was hoping i could see how i compared on these sections with whoever else raced. I can't verify the accuracy of this but it's fun to see. You also have to filter out the year due to course changes from year to year. I created the segments just guessing where it was. I think for the next race i'm at i'll create a lap with my garmin during warmup for each section just to try to be more accurate. Anybody ever messed with this? Here's a couple segments from our race yesterday.