Ride the Selvio Pass on a Ribble SLe

After the last post John Booker (Fred) sent me a very nice youtube video about climbing the Stelvio Pass on a Ribble SLe https://youtu.be/1oooqJQel7E . I have watched it a few times, with the hope of learning how other people use the bike and how it performs. The filming on the video is very professional and describes the climb beautifully, with stunning views. The pass is 21 km long, with an average slope of 8%. The rider said he would apply 150 watts himself, as measured by a power crank. He selected “eco” setting, which I take to be “green”, when the motor supplies 83 watts. He held 7 km/hour through the climb, and the height ascended is 1800 metres. The ride took 3 hours, which fits the speed and distance. At the top there was 15% left in the battery.

How does this compare with the sort of usage I get from the battery on “normal” rides? On “green”, I use approximately 1% battery capacity per kilometre and pedal at about 20 km/hr overall average. So, I use about 20% of battery capacity per hour. The rider who climbed the Selvio used 85% of battery capacity in 3 hours or 28% per hour. I don’t use the battery some of the time because I’m going downhill and stop pedalling, or go more than 25 km/hr, which is the speed the battery cuts out by law. Comparing the two figures above (me 20% per hour and the Selvio climb 28% per hour) it looks as if I don’t use the battery for about 1/3 of the time, which has a reasonable feel for the figure for the rides I do.  

Conclusion – on green setting and pedalling all the time uses about 28% of battery charge per hour, as observed on the Selvio climb. Brilliant! Also, although the rider supplied 150 watts, it looks as if this was the required input to keep the speed at the 7 km/hr. Add more power through the pedals and the rider goes faster. It does not look as though the rider input saves battery. In fact, I don’t think it can because the motor control system would have to be very sophisticated to detect power input through the pedals and adjust the power drawn from the battery.  Rider input adjusts the speed.

What a satisfying conclusion! I might be able to ride the Selvio, maybe needing a range extender because I would take longer or need a higher power for some of the time.