Have you ever wondered how accurate e-bike range estimates are? To find out, I put my Bosch equipped Cannondale Synapse Neo 1 to the test. Assuming the initial estimate is based on nearly ideal conditions with a relatively flat terrain, I chose an out and back route along the Torrey C. Brown Rail Trail, MD and Heritage Rail Trail, PA with a 1,237 foot elevation gain for my test.
With a fully charged battery and the assistance level set at Eco (lowest assist level) the Bosch system estimated that it could provide assistance for 126 miles (see photo on lower left). While I wanted to believe Bosch’s estimate, my route was only 80 miles, giving me a good margin for error. Hopefully, if Bosch’s estimate turned out to be overly optimistic, the shorter route would save me from pedaling a dead e-bike back to my starting point.
The Results? I was pleasantly surprised. After nearly 80 miles (78.60 miles to be exact), I had 3 out of 5 bars (40-60%) left on the battery and an estimated 49 miles remaining (see photo lower right) slightly exceeding the initial estimate.
Initial Range Estimate 
Remaining Range
In the final analysis, the initial estimate was very accurate. In fact, I have to wonder, with about 50% of the battery left, why I didn’t have another 80 miles of assistance remaining. My guess is that Bosch has built in a safety margin to keep the rider from running the battery until it’s completely dead.
Ken Whittaker