As it cools off in my area a bit, I'm getting more motivated to do a bunch of sprocket changes again.
I'm putting together a loop with minimal stops and traffic and will be running on cruise control as much as possible. For speeds, I'm leaning towards doing 2 runs. One favoring the Speedo for Cruise control, one favoring GPS speeds, Just to see how things stack up, for a total of 4 runs.
Data Points to gather on each run:
1. Odometer reading vs GPS mileage reading
2. SOC at start/end
3. Wh/mi avg reading at a known point in the loop
4. Speedo vs GPS reading at 20/40/60 MPH dash
I realize these are only single data points, but I only have so much time/patience for this at this point.
If you want comparable results for different gearing, you need
a fixed route, starting and stopping at the same elevation
fixed speed throughout the course
fixed temperature
no winds
AND
you need to compare how much charge you put into the bike each day- not the bike readout (lots of potential errors).
Even on a fixed route, my daily usage varies a lot.
I commute a fixed route of 83+-1km (depending on map service used to calculate the route). On normal weekdays i charge my SS9+ for just that trip. I get data from the charging box (easee smart charger) which is used solely for the bike.
The lowest consumption i have this year is 5.8kWh one day, maximum is above 10kWh. In August i went relatively consistently below 7 kWh and in May i was mostly at or just below 8 kwh- for the same trip. Wind, temperature and speed has of course everything to do with this. I use significantly less when traversing congested traffic at 20-30 km/h than the usual 80-90 on the same stretches, and wind is generally bad no matter what direction it comes from, because it adds more than it subtracts when going against or sideways vs with its direction.
Adding some data, i have run the bike down to 1% once and then 0% (not stopping) another time. Those days i charged 18.34k and 18.72 kWh, which may or may not seem reasonable considering 18.9kWh advertised capacity, and charge loss is hidden within those figures, so the battery probably stored a few percent less. Range I got was about 230 km as reported by the bike, (i have no better measurement, as i spent the last km's circling very close to home to avoid having to push the bike up hill or for hours.
If the odometer is reasonably accurate i thus got 18,72kWh / 230km = 81,4 Wh/km when emptying the battery- That is a day i was not holding back (i wanted it done) so no slow riding, but no American or German highways either- mostly twisty roads limited around 60-80km/h. Comparably my commute varies from 70 to 120wh/km (typically between 84 and 96 wh/km) - as reported by the charger.
Using the bike to get reported wh/km is meaningless because it uses a moving average of a few km/s. The bike SoC status does change a few percent (around 10% of what is used on a trip of 41.5 km) after the battery has rested for a few minutes, or when temperature changes. SoC is thus not an accurate measure of consumption.
TL:DR Single trip energy usage can be expected to vary quite a lot: 10%+ in similar conditions, and you need to measure consumption outside the bike to get good data.
