Testing for speed

Hooray at last! Due to a sunny period this afternoon I was able to steal some time to test my electric long-board top speed.

Readers of  my recent posts will know  that I have completed the re-purposing and fitting of a bike computer in order to measure distance covered and speed of my electric board. I wanted a permanent device mounted onto my board so it behaved like an odometer in a car. If I ever sold the board there would be a permanent log of the miles covered. But also the intention is that  I can use the real time  speed and distance display to help assess how much more distance I have available before the battery goes flat.

Previously, when initially measuring the board speed through the bike computer I had measured a top speed on the day of 11mph. I have always been curious about how accurate this was, given that the claim from Volo-E for this board is a top speed of 14mph. In the back of my mind I was questioning if  I had calibrated the bike computer correctly and/or if might my weight (85 kg) was significant enough to reduce the total max speed.

The bike computer counts the number of times the wheel rotates by counting the presence of a magnet each time it passes the sensor  in a period of time. I wanted to see if the speed could be measured in an alternative way to verify the bike computer results.

Well today I downloaded the first free iOS app I found  (called WalkFree) to measure my top speed. This app uses GPS to give a much more accurate result then counting wheel rotations. By sampling the GPS positions and taking two of the GPS locations,  the app calculates the distance covered. As with the bike computer, the speed is calculated by distance covered by the time taken (S = d /t).

Well that app recorded a top speed of 11.14 mph! I wasn't able to do exhaustive testing as there were cars interrupting my path. But the good news is both methods report the near same results and it is confirmed that my re-purposed bike computer is doing its job. The bad news is that my electric long-board is slower than I thought :(

Dang, I had a high suspicion that  the only other guy I have seen electric skateboarding in my city had a better performing board than me.....



Don't believe that Vert Drop reading. That remained the same throughout the testing.